Since the last update, I can’t see when anyone calls me

Since I updated my iPhone to the latest software, I no longer see when anyone calls me. Literally nothing happens and then I get a notification saying that I’ve had a missed call/got a voicemail. I’ve checked the focus settings and they’re pretty impossible to understand, but as far as I can tell ‘Do not disturb’ isn’t switched on. Notifications are on. I’ve even reset my phone and it hasn’t made any difference.

I’m self-employed and I’m losing out on business because of this. Can anyone help me please? I’m getting a bit desperate now. Thank you.