I have the S25 ultra unlocked purchased from Samsung on the Verizon network. I keep having a problem when incoming calls half ring and go straight to vm they dont even show up as missed calls. Do not disturb is off. No apps are blocking calls. Even though i didn't have anything on the "block" list I deleted it anyway. Calls are not set to forward.(using Samsung phone app) Outgoing calla and text are fine. I even had Verizon troubleshoot activated a new eSIM worked for 24 hours now have the same problem.
While troubleshooting i wanted to make sure Wi-Fi calling was set to prioritize mobile but cant find that setting anywhere. So for the time being I've turned off WI-FI calling. To see if that helps.
In addition I've "clear cache partition" in the Android recovery setting.
Touch and hold the phone icon, then an applet will pop up. On the top right of the applet you'll see a small circle with an "I" in it, click that. Then go to storage and click that. Then clear both the cache and the data. Before doing that, make sure you're contacts are saved. You may have to customize again though.
