Mobile not recognised replacement SIM

[Marshallrob]

I have 4 mobile contracts all with different numbers about 3 weeks ago all are phones stopped working my sky was not recognising any phone. After contacting Sky mobile they got 3 of the 4 phones working. The 4th phone after doing all the usual network reset, taking sim out then  factory resetting the iPhone 15pro nothing. Sky sent out a replacement SIM card but still nothing works no signal bars on phone, phone is ok as tried another SIM card & all works so I think it is still a SIM but after 3 weeks still nothing works. 

[caesarome]

@Marshallrob 

I know you did a factory reset but have you also tried refreshing the network settings:

Go Settings > General > Transfer or Reset [Device] > Reset > Reset Network Settings. If you're using iOS or iPadOS 14 or earlier, tap Settings > General > Reset > Reset Network Settings. Then go to Settings - Phone - My Number and change it if it is wrong, then reboot the phone. You will need to set up your Wifi connection again.

[Marshallrob]

Thank you for your reply sorry I forgot to mention I did this & checked the number as well.