Phone call interface not showing

[AnotherElk]

Welcome to the community forum.

@AnotherElk

A somewhat common cause of this across many different phones would be Settings - Apps & notifications - See all - Phone - Notifications … could be off in general or could be off in detail for incoming calls.
Else … Do Not Disturb Mode could be activated. Is there something that looks like a “No entry” sign in the status bar?