Daniel Hi! Thanks so much for the suggestions. I wanted to share an update — I actually managed to fix the issue myself.
I tried all the usual steps: clearing the cache, reinstalling the app, wiping the data, and rebooting the phone multiple times. Unfortunately, nothing seemed to work.
In the end, it turned out that the app’s widget was the culprit. Somehow, it was slowing down the app so much that it wouldn’t load messages or allow me to send any. As soon as I removed it, everything started working perfectly again. It’s a shame I had to remove the widget, because it was really handy.
Honestly, this shouldn’t happen after an OS update — it feels like something the devs should definitely fix.
Hope this helps someone else facing the same problem!