Phone won't activate after resetting.
I've had an HTC One M7, after a couple of months, the phone had to be factory reset (the power button was beginning to fail and was glitching out constantly turning on and off and just spamming itself repeatedly.) After I removed the power button I tried to reactivate my phone to no avail. I am using the same phone and the same SIM card so either I am activating the phone wrong, or there is an issue with the account and my phone now. I can still use the messaging and calling functions of the phone over wifi, but i cannot activate the phone with mobile data. Any assistance with this would be greatly appreciated.