Steps to reproduce:
Step 1: Install DB version 10.1.14
Step 2: Upgrade DB to 10.4.10
mysql_upgrade reports errors as seen in attached log.
The errors are for a compound index on a table with 721 partitions.
All partitions are pre-created during install/upgrade.
Partitions uses values less than date to organize the data - one partition for each day.
Each day a new partition is used to store data into this table called history.
Data older than 721 days is deleted from the table by dropping the oldest partition.
Table DDL:

create table `history` (
`value_key int(11) not null,
`timestamp` datetime not null,
`valuei` int(11),
`group_id` int(11) not null default 0,
unique index `idx_value_id_timestamp`(`value_key`, `timestamp`, `group_id`)