Hi @Vardre
If you and your wifes phone are the same make/model, have you compared the individual settings between each of the handests to make sure they are the same? Sometimes it is the simplest detail that makes all the difference.
If it is only your SIM that has a problem connecting, when trying to make a call with either handset, then it may be worth getting a replacement SIM:-
To get a replacement SIM card, log in to the iD Mobile app or your account online, click on Plan and the go to SIM & Phone Management > Request a replacement SIM, which will then be sent to you and which usually arrives within 2-3 days. Alternatively, you can either chat with an iD Mobile agent or visit a Currys store for an immediate replacement.
If you wish to do this via an adviser on Live Chat:-
https://www.idmobile.co.uk/live-chat
Type ‘talk to a person’ in the dialogue box to connect to an adviser.
(available 9am - 8pm Monday to Friday, and 9am - 6pm Saturday, Sunday, and Bank Holidays)
Just be aware that your account will be paused and you will not be able to use your phone until the replacement SIM has been activated.
Good luck x