This seems to be an Android induced bug, I have used other SIP clients which also have this problem when running on my Samsung A32 with Android 12.

There are few problems you can only select "notification tones as ringtones" - After selecting it - it didn't ring for me. Then I had to choose by trial and error the options in Ringer Player, Currently I have set it to Notification Stream and it plays the ringtone when a call arrives

Under general settings, run in background yes, display notification - for calls only, enable push - no, scheduled wakeup - Force.

With the above settings I am able to get ringtone.

I used to get early media as per the SIP server's choice i.e a UK ringtone, however I only get the long ringtone US.Europe after changing the SIP Settings -> Ring on Session Progress options. Whichever I choose it is now playing the long ringtone and not what the SIP gateway tells it to play.