Can't answer calls

[Easypeeler]

A week ago I bought a SAMSUNG S20FE5g via an upgrade on my O2 account. I can't answer incoming calls - nothing happens when I tap on the green circle at bottom to try and accept a call - the ringing tone just carries on until the call ends with an invitation to leave a voicemail. I consider that Samsung have delivered me a product that is not of merchantable quality - basically the phone doesn't function properly. Any suggestions out there (and no I don't want to keep turning the phone on an off, thanks).

[Markiep]

have you tried swiping the green circle up?

[Easypeeler]

Yay! Thanks for that Markiep

[MartynaK]

@Easypeeler,

I am glad to hear that the problem has been resolved! 😀

@Markiep thanks so much for your precious help! 

[Permfloat]

I have the same issue now in 2023. Phone rings but answer button does do anything either tapping or swiping. Very disappointing. 
don’t want to press volume up each time.