Hi @Gph1952
Thank you for your message, and I’m sorry for the ongoing issues with your ported number. I completely understand your concern about this potentially causing problems in the future.
Since your number is still not appearing under “My Number” or in the iPhone settings, even after switching SIMs and restarting, this indicates that the port hasn’t fully completed on the device level, even though your phone is otherwise working.
Please go to Settings> Phone> My Number.
Please change it to the number you wish to keep. It might not allow to change or save immediately.
If you are still unable to save the number, please open the Settings app. Tap General. Scroll down to the bottom of the list. Tap Reset. The "Reset" option is at the bottom of the Settings menu. ... Tap Reset Network Settings. Enter your passcode if prompted, then tap Reset Network Settings to confirm your choice. This will help.
Thank you,
Zandile