Phone calls dropping out

[Olivia1]

I have a new Samsung s20 plus Nearly 80% off my calls drop out mid conversation, can I do anything.

[MI5]

@Olivia1 

If you are not in a 5g area, check that 5g is not enabled in your network settings.

Also check for any faults here O2 Service Status

and some help here Guide: How can I sort out my network issues?