IMessage trouble with old and new ported number

[CakeTin]

Hi there, 

I recently got an iPhone 12 on an 02 plan. I moved from EE but ported my old number over. However IMessage and FaceTime won't connect to my old number - saying Activation Unsuccessful. When I go into the Phone settings, it's saying the number of the phone is the new SIM number, and when I try to change it manually it won't save. Any help would be appreciated, thanks 

[MI5 · Accepted solution]

@CakeTin 

First step is to reset your network settings.

If it still fails save your number, you will need to get a new sim and do a sim swap Guide: Sim Swap: a mini guide 2017 update 

If you message O2 on Facebook (https://o2uk.co/O2CFB) , Twitter (https://o2uk.co/O2CTW) or Instagram (https://o2uk.co/O2CIG) , they should be able to help you with this
Thanks

[CakeTin]

Ah the network reset has worked, it now recognises my old number as the main number on the phone. Thank you for that. There’s still a problem with connecting to IMessage and FaceTime but I read a few other forums that said it will sort itself out in a few days. 

[MI5]

@CakeTin 

Yes, it has been known for it to activate by itself after a few days.

It should be fine now your correct number is showing.