Samsung phones will keep trying to update when T Mobile sends out an update to its branded phones.
Keep doing what you are or perhaps look into Custom Roms.
Xdadevelopers site is a good place to start.
Disclaimer.....
however that can come hand in hand with making the phone unstable or unusable if the process goes wrong.
Daily Driver > Samsung Galaxy s²³ Ultra 512Gb in Phantom Black.
The advice I offer is my own and does not represent Samsung’s position.
I'm here to help. " This is the way. "
