calls keep hanging up

[Unicorn94]

Hi,I have just switch to the Samsung S20 and the only problem i have with it is that everytime I make a call it will hang up, sometimes it's 10 minutes in sometimes its five minutes sometimes longer, I have unlimetted texts and calls so i dont understand why its happeneing! It's really annoying!

please any advise  

[MI5]

@Unicorn94 

Check for network faults here O2 Service Status

If the problem persists, you may wish to try a new sim card.

You'll need to call customer service.
Numbers here Guide: Coronavirus Community Help and Support 
When it comes to the reason you are calling stay silent for 15 seconds and you will be taken to the keypad options.
Press 2 for Everything Else
Press 5 for More Options
Press 7 for Anything Else which will put you though to someone.
Say "Upgrade", "Lost/Stolen" or "Fraud" if you have to, to get put through to someone.
8.00am is the best time to call if you can.

[paulbacon]

Having 4g calling enabled if in a weak 4g area can cause this. Did with my phone until i disabled 4g calling before 4g became more widespread in my area