Upgrading from 14.9.x to 14.10.5 (up to 15.1.x now) produces many SQL errors (each UNION query must have the same number of columns..)

Hello,

we are using the Debian packages of gitlab and since we have updated them from 14.9.x to 14.10.5 (at the moment we are on 15.1.x still with the same problems) we get on different pages a 500 http errors, which comes from a sql error:

ActiveRecord::StatementInvalid (PG::SyntaxError: ERROR:  each UNION 
query must have the same number of columns
LINE 5: (SELECT "namespaces".* FROM "namespaces" INNER JOIN "group_g...

The search is partially broken, listing of all subgroups and projects is broken for non-admins (for gitlab admins it works) which makes the biggest headaches for us. You can find all related logs and queries I found for this in this bugreport: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1014904

I hope you can help