MariaDB: Aborted connection 9 to db: 'unconnected' user: 'unauthenticated' host

I could not get a docker-based project to run; the SQL server could never be reached:

db_1     | 2021-02-16  8:10:16 8 [Warning] Aborted connection 8 to db: 'unconnected' user: 'unauthenticated' host: '172.24.0.3' (This connection closed normally without authentication)
db_1     | 2021-02-16  8:10:16 9 [Warning] Aborted connection 9 to db: 'unconnected' user: 'unauthenticated' host: '172.24.0.3' (This connection closed normally without authentication)

Our docker-compose.yml file had "image: mariadb", which fetched mariadb 10.4.12.

The error went away when pinning the version to "image: mariadb:10.2".