Ok so would be helpful when asking for help that you give the full story.
I would suggest getting a free O2 PAYG SIM (or you can buy them from supermarkets for 49p or 99p).
Turn WiFi off.
Take current SIM out
Pop O2 SIM in
Let it connect to 4g / 5g then wait a few minutes
Turn WiFi back on
Try to update
Settings
Software update
See if that fixes the issue. If it does, there may be multiple updates to be uploaded which need to be done one at a time.
Once all done (assuming it works) then you can now pop your three SIM back in.
I am not employed by Samsung nor do I receive any remuneration as a Samsung Members Star.
My device is an S25 Ultra.