Face tags not updating or showing in 8.5.0 (Mac)

I made a big change to my digikam setup recently:

  1. I moved from intel mac (Monterey) to apple silicon (Sequoia)
  2. I upgraded from v8.3.0 to v8.5.0 of digikam and OK’d a database update dialog (and because of the problems below am trying 8.6.0).

My collection is on a removable disk and the database uses MySQL Internal server (but for reasons I can’t remember it was running via a homebrew install of mariadb on the Intel Mac).

On upgrading face tags do not show up and the application doesn’t recognise changes to the tagging information (i.e faces that were not previously confirmed stay unconfirmed) even though sidecars and db_data files look like they are being updated.

I’ve tried:
using maintenance tools to clean up and sync the database.
using the old digikamrc file

Because all this hasn’t worked I’ve also tested making a new database from scratch and can only get SQLite to set up and work correctly (on an ‘empty’ collection).
MySQL Internal gives an error ‘Could not start database initializer’
(using the internal mariadb path and new homebrew locations for mariadb)
MySQL Server can’t find a socket (I can set up a database itself with the required settings)

I’m a complete novice with MySQL/mariadb (I’m not sure what trick I used to get it set up previously).

Any help would be great.

I have now managed to create a new external database, but obviously it doesn’t have the old information!
(specifically I’m using 127.0.0.1 as the host and a user named digikam).

There are no problems with the face tags showing up now, just I guess I’ll have to start from scratch.