I had to uninstall Tidal HiFi to log back into Strawberry Tidal
I don't understand what's this issue with the tidal-hifi app at all. I can use both at the same time. Assuming you mean this app.
again reinstalling and now I can no longer update any playlists, authors, tracks, or albums. The tab closes instantly after starting a search, being impossible to give any results. Only the search for a particular row or author works.
Which version. Say the full build filename.
Have you deleted/renamed these user config folders whenever you have reinstalled Strawberry, even once as a test? It is not normally needed but something in the database might be messed up considering all the weird issues you're having.
Rename them to something. Launch Strawberry, login to Tidal and see if the problems still persist. If they do then undo the renaming and you'll lose no settings.
I give up my collection in Strawberry.
Don't worry about losing it since it is always synced back your Tidal account.