Likely you were still on Nougat stable and on this particular device never before experienced an Android version upgrade. Sounds like your /e/ shop purchased phone was in a similar position to this older post Pre-installed S7: Nougat or Oreo?.
Here is a weekly update from the summer when the significant change happened Week 23, 2022: Development and Testing Updates please read all that applies to your position. As a result of this the now unsupported Nougat builds were withdrawn.
So going back is not an option!
Regarding apps which misbehave after this 3 Android version upgrade we had this note re Signal S7/S7+ upgrade related issue. Some other apps were similarly affected. In case of problems just try to install a current version of the app.
Most users have found versions 1.2 and 1.3 a significant improvement on 1.0, I would upgrade to 1.3.