Not receiving text messages

[PayMonthly1]

Hi,

I recently upgraded from a Hauwei phone to a Samsung Galaxy Note 10. I took the sim card out of my old phone and put it into the new one. I installed an app that sent a code via text message, which was fine, but since then I have not received any text messages. Whenever my husband texts me, he gets a notification saying "recipient is offline". I've tried clearing the message cache and made sure the app had all permissions in place but still no luck. If anyone can offer any help or advice it would greatly appreciated. Thanks.

Will.

[MI5]

Try removing the sim and reinserting it.

@PayMonthly1 

Text tips here too Guide: Text Message Tips (not sent or received) 

[PayMonthly1]

Hi, I just tried that and I'm still not receiving text messages and my husband is still getting a notification saying that I am offline.

[MI5]

Delete whichever app you installed.

[PayMonthly1]

I tried that, but it didn't help. I seem to have made some progress by putting a new sim card and doing the sim swap thing. I have been able to receive text messages from o2 and my bank, but still not my husband or work colleagues.
The new sim card seems to be up and running otherwise, however the sim card status screen says "IMS Registration Status: Not Registered" and, according to Google, that can cause errors when sending/receiving texts and phone calls.
Any advice on how to fix this as I think this may be the issue? Thanks.