Text Messages Issue - Urgent!

[Bumbledog]

My partner, who is medically extremely vulnerable, has recently changed her phone to a Samsung A71 from her old Huawei. The new phone has had all her information transferred over correctly, and her old number was transferred to her new sim via ringing O2 (her old phone was a Carphone Warehouse O2).

The issue is;

She can send texts to my phone with no issues, but when I reply to her new phone via my Google Pixel 3XL O2 phone, the texts go to her OLD phone. Even though this phone says emergency only. Texting from her Father's old Doro O2 phone goes through fine to her new phone.

I thought it might have been an issue with my Pixel 3XL, so I did a complete factory reset of my phone.. which is a bit of a pain, and it seemed to resolve the issue for a short while. But today the problem of her not receiving my texts on her new phone has re-appeared.

This is worrying for both myself and her, due to issues that might arise with Covid alert texts.

Her message number is set correctly, as is mine.

Solution please anyone?

[Cleoriff]

@Bumbledog 

A few things to check here Guide: Text Message Tips (not sent or received) 

Try those first and if still having problems I'll ask one of our account advisors to help

@O2Lisaand @O2Daniel  are you able to help here?

[O2Lisa]

Thanks for the tag @Cleoriff 

I'll message you privately @Bumbledog and look further in to this for you 

[Cleoriff]

Thanks @O2Lisa 

[Bumbledog]

Thanks for the reply. All those steps have been done already. As i posted, it all worked after I did a factory reset on my phone until late last night when the issue started again. I am not willing to do another reset on my phone again though as it takes ages to relog into banking apps etc.