As mentioned in the AWS discussion forum back in October, Amazon has started the end of life (EOL) process for RDS MySQL version 5.5. What this means is: AWS will upgrade RDS instances to MySQL 5.7 starting February 9 2021 00:00 UTC during your next defined maintenance window, provided you have one. If you dont [&]

https://www.percona.com/blog/2020/12/21/amazon-rds-for-mysql-5-5-eol-date-is-approaching-act-now/