QuietScrob on iOS/iPadOS works pretty well - it seems any breakage is due to Apple silently changing APIs more than anything on the dev's end.

On Desktop (macOS) I use the official Last.FM app - however it's still a Rosetta 2 app which will be sunset in the fall :(

On desktop devices, I'm using Cider.sh which supports scrobbling, and on Android I use Pano Scrobbler.