You're not alone — this seems to be a bug affecting some users after updating to Android 15. The phone rings, but the call UI doesn't appear, so you can't answer. A few things you can try:
Restart your phone – this fixes it temporarily for some users.
Clear cache of the Phone app (Settings > Apps > Phone > Storage > Clear Cache).
Check default apps – make sure your Phone app is set as the default for calls.
Safe mode – boot into safe mode to see if a third-party app is causing the issue.
If the issue persists, consider reporting it via Samsung Members or your device’s feedback tool so it can be patched in a future update.
