Since iOS 15.2 update I can no longer make calls from my contacts with international dialling codes.
Apple genius (2 appointments + Apple store manager conversation - Apple Covent Garden) undertook the following tests - at no point even after requests, did they do a hardware test or ask to take user logs.
Turned on and off dial assist
Hard reset
Reset network settings
Reset all settings
Total phone wipe & reinstall as new phone (not using icloud backup)
All failed to resolve the issue.
I was advised to edit each of all my +300 contacts by removing either the international dialling code or leaving that and removing the domestic (0)……Great Apple!
Apple genius seemed uninterested but I was assured the issue would be resolved in a future update! Helpful!