I just gave up and bought a new (secondhand) phone at the beginning of this year. I returned one of my older phones (Galaxy Note 9) to stock as a backup but I’m not even sure if that will work now because it’s a grey import (even though it has working VoLTE currently and supports all Australian network bands). It’s a bit sad that I have this little collection of otherwise great older phones that still receive updates to their custom ROMs but will now be useless as phones.