Hi @scouserjay
Have you checked to see the coverage or if there are any works in your area recently?
https://www.idmobile.co.uk/help-and-advice/coverage
Do you have VoLTE enabled on your handset?
- VoLTE is voice calls over a 4G LTE network. Choose Next to see instructions on how to enable/disable VoLTE. ...
- Go to the Start screen. ...
- Choose Settings.
- Scroll down. ...
- Choose Mobile networks.
- Enable 4G call SIM 1.
- VoLTE has been activated.
It may be worth requesting a replacement SIM:-
Just be aware that your account/use will be on hold until your new SIM is activated.
This is what I have found via Google with regards to this update (as of 14/14/25):
‘The long-awaited One UI 7 update didn’t last long. After months of delays, the update was launched last week, but Samsung has already paused its rollout and pulled it from its servers. This is due to what leakers call a “serious bug,” and although Samsung itself hasn’t confirmed anything, we’re inclined to agree that it sounds pretty serious indeed.’
Unfortunately, once your software has been updated you can not go back to the previous version and can only wait for another update to fix the problem.
If you Google (other search engines are available) ‘samsung S24 One UI 7 calls problems’ you will see that this update may be the problem.
Apologies I couldn’t be of more help x