@daniel-b Can you please give us a little more information about your setup? I.E. The configuration, the version of FusionAuth you are using, the version of MySQL etc?
According to the docs FusionAuth supports MySQL 8.0 or newer. More specifically:
MariaDB and Percona may work, however these variants are not actively tested against by FusionAuth.
See MariaDB known issues on our GitHub issues.