Helge Heß on Nostr: The implementation obviously does matter 🙂 I suspect the db.connect in the MySQL ...

The implementation obviously does matter 🙂 I suspect the db.connect in the MySQL driver doesn't give you an actual connection but a proxy that will open a connection when necessary (i.e. is a pool). While the SQLite one gives you an actual connection, which you then can't share between threads.
So yes, that seems like an unfortunate difference in the implementation of the two drivers in your environment. Not great. (i.e. you should file a bug w/ the Go SQLite driver)