Okay, if anyone is seeing this I managed to move this instance from a server in Sweden to a server in Germany (edit: Oops. Actually: Finland), managing to copy and restore the database, and hopefully keeping most stuff intact… 😅
If things are “misbehaving” for a while longer it’s because the domain name has moved to a new ip address and that pointer has to be removed and refreshed in various caching systems.
I am learning so much and having great fun experimenting, I have to say.