While installing ibexa/oauth2-server package, I encountered some foreign key errors because ibexa_oauth2_ tables were created with default character set and collation not matching the foreign keys' ones.

I created the tables by piping the schema to the mysql client (ddev php bin/console ibexa:doctrine:schema:dump-sql vendor/ibexa/oauth2-server/src/bundle/Resources/config/schema.yaml | ddev mysql), and it used default/random charset and collation (existing ezuser was using utf8mb4_unicode_520_ci for its VARCHAR columns while created ibexa_oauth2_consent was using utf8mb3_unicode_ci). I fixed this at db server level; I reported my fix to DDEV doc into https://github.com/ibexa/documentation-developer/pull/2481/files

It's an issue that might occur on other MySQL/MariaDB installations than with DDEV, or to other database manipulation than adding the oauth2-server schema