Hanging up current call when there is another call incoming

Bought my iPhone 11 about 6 months ago and it keeps doing this strange thing. When I'm in call with somebody, if I have another incoming call while I talk, the phone automatically hangs up the current call and answers the one incoming. Does this without asking me if I want to decline the new call or put it on hold. Does this very often. Sometimes it asks me but more often not. Is there a fix or setting for this? It's really annoying. Already tried restarting and reseting the phone.