diff --git a/mysql-test/suite/percona_innodb/r/ps_9616.result b/mysql-test/suite/percona_innodb/r/ps_9616.result
new file mode 100644
index 000000000000..c8f478ec10e8
--- /dev/null
+++ b/mysql-test/suite/percona_innodb/r/ps_9616.result
@@ -0,0 +1,109 @@
+# utf8mb4_general_ci ===>>> utf8mb4_0900_ai_ci ### in 2 steps
+CREATE TABLE `test_table`
+(
+`field1` varchar(10) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci DEFAULT NULL,
+`field2` text CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_general_ci;
+ALTER TABLE test_table
+MODIFY field1 varchar (10) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci DEFAULT NULL,
+MODIFY field2 text CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci,
+ALGORITHM=INPLACE;
+ALTER TABLE test_table COLLATE=utf8mb4_0900_ai_ci, ALGORITHM=INPLACE;
+SHOW CREATE TABLE test_table;
+Table	Create Table
+test_table	CREATE TABLE `test_table` (
+  `field1` varchar(10) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci DEFAULT NULL,
+  `field2` text CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci
+DROP TABLE test_table;
+# utf8mb4_general_ci ===>>> utf8mb4_0900_ai_ci ### in 1 step
+CREATE TABLE `test_table`
+(
+`field1` varchar(10) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci DEFAULT NULL,
+`field2` text CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_general_ci;
+ALTER TABLE test_table
+MODIFY field1 varchar(10) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci DEFAULT NULL,
+MODIFY field2 text CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci,
+COLLATE=utf8mb4_0900_ai_ci,
+ALGORITHM=INPLACE;
+SHOW CREATE TABLE test_table;
+Table	Create Table
+test_table	CREATE TABLE `test_table` (
+  `field1` varchar(10) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci DEFAULT NULL,
+  `field2` text CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci
+DROP TABLE test_table;
+# with indexed columns
+CREATE TABLE `test_table`
+(
+`field1` varchar(10) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci DEFAULT NULL,
+`field2` text CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci,
+INDEX(`field1`),
+INDEX(`field2`(10))
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_general_ci;
+ALTER TABLE test_table
+MODIFY field1 varchar (10) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci DEFAULT NULL,
+MODIFY field2 text CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci,
+ALGORITHM=INPLACE;
+ERROR 0A000: ALGORITHM=INPLACE is not supported. Reason: Cannot change column type INPLACE. Try ALGORITHM=COPY.
+ALTER TABLE test_table COLLATE=utf8mb4_0900_ai_ci, ALGORITHM=INPLACE;
+SHOW CREATE TABLE test_table;
+Table	Create Table
+test_table	CREATE TABLE `test_table` (
+  `field1` varchar(10) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci DEFAULT NULL,
+  `field2` text CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci,
+  KEY `field1` (`field1`),
+  KEY `field2` (`field2`(10))
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci
+DROP TABLE test_table;
+# utf8mb4_general_ci ===>>> utf8mb4_0900_ai_ci ### in 1 step
+CREATE TABLE `test_table`
+(
+`field1` varchar(10) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci DEFAULT NULL,
+`field2` text CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci,
+INDEX(`field1`),
+INDEX(`field2`(10))
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_general_ci;
+ALTER TABLE test_table
+MODIFY field1 varchar(10) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci DEFAULT NULL,
+MODIFY field2 text CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci,
+COLLATE=utf8mb4_0900_ai_ci,
+ALGORITHM=INPLACE;
+ERROR 0A000: ALGORITHM=INPLACE is not supported. Reason: Cannot change column type INPLACE. Try ALGORITHM=COPY.
+SHOW CREATE TABLE test_table;
+Table	Create Table
+test_table	CREATE TABLE `test_table` (
+  `field1` varchar(10) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci DEFAULT NULL,
+  `field2` text CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci,
+  KEY `field1` (`field1`),
+  KEY `field2` (`field2`(10))
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_general_ci
+DROP TABLE test_table;
+# ADD INDEX + AUTO_INCREMENT= in 1 step
+CREATE TABLE test_table (a INT, b INT) ENGINE=InnoDB;
+ALTER TABLE test_table ADD INDEX idx_b(b), AUTO_INCREMENT=7, ALGORITHM=INPLACE;
+SHOW CREATE TABLE test_table;
+Table	Create Table
+test_table	CREATE TABLE `test_table` (
+  `a` int DEFAULT NULL,
+  `b` int DEFAULT NULL,
+  KEY `idx_b` (`b`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci
+DROP TABLE test_table;
+# DROP INDEX + COLLATE= in 1 step
+CREATE TABLE `test_table`
+(
+`field1` varchar(10) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci DEFAULT NULL,
+INDEX(`field1`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_general_ci;
+ALTER TABLE test_table
+DROP INDEX field1,
+COLLATE=utf8mb4_0900_ai_ci,
+ALGORITHM=INPLACE;
+SHOW CREATE TABLE test_table;
+Table	Create Table
+test_table	CREATE TABLE `test_table` (
+  `field1` varchar(10) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci DEFAULT NULL
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci
+DROP TABLE test_table;
diff --git a/mysql-test/suite/percona_innodb/t/ps_9616.test b/mysql-test/suite/percona_innodb/t/ps_9616.test
new file mode 100644
index 000000000000..83b37e88b880
--- /dev/null
+++ b/mysql-test/suite/percona_innodb/t/ps_9616.test
@@ -0,0 +1,118 @@
+--echo # utf8mb4_general_ci ===>>> utf8mb4_0900_ai_ci ### in 2 steps
+CREATE TABLE `test_table`
+(
+    `field1` varchar(10) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci DEFAULT NULL,
+    `field2` text CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_general_ci;
+
+
+# ha_alter_info->handler_flags = ALTER_COLUMN_EQUAL_PACK_LENGTH & ALTER_COLUMN_DEFAULT
+ALTER TABLE test_table
+    MODIFY field1 varchar (10) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci DEFAULT NULL,
+    MODIFY field2 text CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci,
+    ALGORITHM=INPLACE;
+
+# ha_alter_info->handler_flags = CHANGE_CREATE_OPTION
+ALTER TABLE test_table COLLATE=utf8mb4_0900_ai_ci, ALGORITHM=INPLACE;
+
+SHOW CREATE TABLE test_table;
+
+DROP TABLE test_table;
+
+
+--echo # utf8mb4_general_ci ===>>> utf8mb4_0900_ai_ci ### in 1 step
+# before the patch, this innodb created a new table
+# check with SET GLOBAL innodb_print_ddl_logs = ON; SET GLOBAL log_error_verbosity = 3;
+
+CREATE TABLE `test_table`
+(
+    `field1` varchar(10) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci DEFAULT NULL,
+    `field2` text CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_general_ci;
+
+# ha_alter_info->handler_flags = ALTER_COLUMN_EQUAL_PACK_LENGTH & ALTER_COLUMN_DEFAULT & CHANGE_CREATE_OPTION
+ALTER TABLE test_table
+    MODIFY field1 varchar(10) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci DEFAULT NULL,
+    MODIFY field2 text CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci,
+    COLLATE=utf8mb4_0900_ai_ci,
+    ALGORITHM=INPLACE;
+
+SHOW CREATE TABLE test_table;
+
+DROP TABLE test_table;
+
+--echo # with indexed columns
+CREATE TABLE `test_table`
+(
+    `field1` varchar(10) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci DEFAULT NULL,
+    `field2` text CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci,
+    INDEX(`field1`),
+    INDEX(`field2`(10))
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_general_ci;
+
+
+--error ER_ALTER_OPERATION_NOT_SUPPORTED_REASON
+ALTER TABLE test_table
+    MODIFY field1 varchar (10) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci DEFAULT NULL,
+    MODIFY field2 text CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci,
+    ALGORITHM=INPLACE;
+
+ALTER TABLE test_table COLLATE=utf8mb4_0900_ai_ci, ALGORITHM=INPLACE;
+
+SHOW CREATE TABLE test_table;
+
+DROP TABLE test_table;
+
+
+--echo # utf8mb4_general_ci ===>>> utf8mb4_0900_ai_ci ### in 1 step
+# before the patch, innodb created a new table
+# check with SET GLOBAL innodb_print_ddl_logs = ON; SET GLOBAL log_error_verbosity = 3;
+
+CREATE TABLE `test_table`
+(
+    `field1` varchar(10) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci DEFAULT NULL,
+    `field2` text CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci,
+    INDEX(`field1`),
+    INDEX(`field2`(10))
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_general_ci;
+
+--error ER_ALTER_OPERATION_NOT_SUPPORTED_REASON
+ALTER TABLE test_table
+    MODIFY field1 varchar(10) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci DEFAULT NULL,
+    MODIFY field2 text CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci,
+    COLLATE=utf8mb4_0900_ai_ci,
+    ALGORITHM=INPLACE;
+
+SHOW CREATE TABLE test_table;
+
+DROP TABLE test_table;
+
+# Verify that combining ADD INDEX with AUTO_INCREMENT= does not crash the
+# server (regression: INNOBASE_INPLACE_NO_REBUILD incorrectly masked ADD_INDEX,
+# causing prepare/alter to early-exit while commit tried to find the unbuilt index).
+--echo # ADD INDEX + AUTO_INCREMENT= in 1 step
+CREATE TABLE test_table (a INT, b INT) ENGINE=InnoDB;
+
+ALTER TABLE test_table ADD INDEX idx_b(b), AUTO_INCREMENT=7, ALGORITHM=INPLACE;
+
+SHOW CREATE TABLE test_table;
+
+DROP TABLE test_table;
+
+# Verify that combining DROP INDEX with COLLATE= in one INPLACE
+# step does not silently discard the index drop.
+--echo # DROP INDEX + COLLATE= in 1 step
+CREATE TABLE `test_table`
+(
+    `field1` varchar(10) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci DEFAULT NULL,
+    INDEX(`field1`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_general_ci;
+
+ALTER TABLE test_table
+    DROP INDEX field1,
+    COLLATE=utf8mb4_0900_ai_ci,
+    ALGORITHM=INPLACE;
+
+SHOW CREATE TABLE test_table;
+
+DROP TABLE test_table;
diff --git a/storage/innobase/handler/handler0alter.cc b/storage/innobase/handler/handler0alter.cc
index 258149ba6009..bad5f4b591ec 100644
--- a/storage/innobase/handler/handler0alter.cc
+++ b/storage/innobase/handler/handler0alter.cc
@@ -931,10 +931,12 @@ static inline bool is_instant(const Alter_inplace_info *ha_alter_info) {
     return (false);
   }
 
-  Alter_inplace_info::HA_ALTER_FLAGS alter_inplace_flags =
-      ha_alter_info->handler_flags & ~(INNOBASE_INPLACE_IGNORE);
+  bool has_change_create_option =
+      (ha_alter_info->handler_flags & ~INNOBASE_INPLACE_IGNORE &
+       ~Alter_inplace_info::ALTER_COLUMN_EQUAL_PACK_LENGTH) ==
+      Alter_inplace_info::CHANGE_CREATE_OPTION;
 
-  if (alter_inplace_flags == Alter_inplace_info::CHANGE_CREATE_OPTION &&
+  if (has_change_create_option &&
       !(ha_alter_info->create_info->used_fields &
         (HA_CREATE_USED_ROW_FORMAT | HA_CREATE_USED_KEY_BLOCK_SIZE |
          HA_CREATE_USED_TABLESPACE))) {
@@ -5960,7 +5962,8 @@ bool ha_innobase::prepare_inplace_alter_table_impl(
   }
 
   if (!(ha_alter_info->handler_flags & INNOBASE_ALTER_DATA) ||
-      ((ha_alter_info->handler_flags & ~INNOBASE_INPLACE_IGNORE) ==
+      ((ha_alter_info->handler_flags & ~INNOBASE_INPLACE_IGNORE &
+        ~Alter_inplace_info::ALTER_COLUMN_EQUAL_PACK_LENGTH) ==
            Alter_inplace_info::CHANGE_CREATE_OPTION &&
        !innobase_need_rebuild(ha_alter_info))) {
     if (heap) {
@@ -6002,9 +6005,8 @@ bool ha_innobase::prepare_inplace_alter_table_impl(
       }
       return dd_prepare_inplace_alter_table(m_user_thd, ctx->old_table,
                                             ctx->new_table, old_dd_tab);
-    } else {
-      return false;
     }
+    return false;
   }
 
   /* If we are to build a full-text search index, check whether
@@ -6215,7 +6217,8 @@ bool ha_innobase::inplace_alter_table_impl(TABLE *altered_table,
     return all_ok();
   }
 
-  if (((ha_alter_info->handler_flags & ~INNOBASE_INPLACE_IGNORE) ==
+  if (((ha_alter_info->handler_flags & ~INNOBASE_INPLACE_IGNORE &
+       ~Alter_inplace_info::ALTER_COLUMN_EQUAL_PACK_LENGTH) ==
            Alter_inplace_info::CHANGE_CREATE_OPTION &&
        !innobase_need_rebuild(ha_alter_info))) {
     return all_ok();