calls randomly not working

[Farinos]

Anyone having their calls just stop working now and again and having to restart phone to get them going again? A few times now I've gone to make calls, it rings then I get nothing and also same with incoming,  phone rings I answer then nothing but silence

[Mimo40]

has all this been happening after an update?

[Farinos]

not sure, not really had phone long enough to notice whether it was happening before an update or not, plus I really don't make that many calls

[JoB1978]

I have this with my s10+ it will say not registered on a network and I have ti restart a few times before it will do anything

[Mimo40]

what you could do just as a piece of mind is clear phone cache just incase it software causing the problem. And if it is not that then it's possible sim problem.

https://www.hardreset.info/devices/samsung/samsung-galaxy-s21-ultra/wipe-cache/

[Farinos]

thanks, I'll give it a go

[Mgordon]

I started having this problem last week. I am ready to send my phone back.

[Farinos]

mines not done it since I cleared the cache in the phone app.
could be worth trying that

[Mgordon]

I do a restart and it does solve the problem but only for a little while. 

I will certainly try that -how do i clear the cache?

Thanks

[Farinos]

settings, go to apps ,go to phone, click on storage then clear cache