How can I configure Do Not Disturb so calls don't interrupt a Teams meeting?

When I'm connected to a Bluetooth headset, it seems Do Not Disturb is meaningless. I turn it on (sometimes allowing Starred Contacts to interrupt, sometimes none) and put on my earbuds to work, alternating between listening to media and joining Teams meetings. Unknown callers, suspected spam and even my ex-wife ring right thru and interrupt the audio of my meetings. Even if I decline the call, it takes several seconds more meeting audio to return to my headset. Please help. If I'm giving a presentation and it's interrupted one more time by the phone ringing from someone I wouldn't answer even without DnD active I might do something drastic, like buying an iPhone. By the way, I still love my Pixel 2, but I'll upgrade if that will fix this travesty.