I'm trying to upgrade an RDS database cluster engine from Aurora PostgreSQL 9.6.19 before its end of life, I made copy and tried to upgrade to 9.6.21 and 10.16 but everytime the same problem happens:
Database cluster is in a state that cannot be upgraded: Postgres cluster is in a state where pg_upgrade can not be completed successfully.
The status of the database is Available so maybe it refers to something else but I don't know what and how to fix it, I've tried looking for answers to no avail.
Has anyone fixed this?