I'm running the latest Bookworm, originally dist-upgraded from stable. An update approximately 1 to 1-1/2 weeks ago broke operation with US Mobile cellular provider. Previously, the status banner icon reported "US Mobile" (an MVNO) as my carrier. Now it reports "T-Mobile" (which is the network used with US Mobile "White" SIM cards). I can no longer use cellular data at all. All web requests are re-routed to a T-Mobile page that reports that I need to subscribe to data. My online US Mobile account page reports that I have plenty of data remaining. Voice and SMS text still work but I can no longer connect to the Internet via wifi for web or apt-get update / upgrade / dist-upgrade without disabling Mobile data service first, because the requests are routed through cellular mobile service instead of wifi. Previously, wifi data had priority over cellular data. My wife's Pinephone, also running Bookworm but not updated regularly functions with US Mobile as it should. We have the same plan. Booting to an old version of Mobian from megi's multiboot SD card also results in correct function with US Mobile. I'm thinking that I'll have to save my /home directory and restore my system with an image from my wife's phone and adopt her approach of avoiding Mobian updates, unless each update is preceded by a making a backup system image.