IPhone Keeps Ringing in Silent Mode

I’ve seen several threads about this. My iPhone 11 with current update keeps randomly ringing in Silent Mode. I have the switch turned to silent. Even have sound turned down in the Sounds & Haptics settings. These are not people set as emergency contacts. And they are not people set as favorites. It is random and even when the same person calls, sometimes it will ring with volume and sometimes it won’t. My work requires my phone to be silent so desperate to figure out what is going on.