Mic picks up headphone

When I have multiple players in my Lobby, often one of the players will hear their voice coming from another player. I suspect that this is due to the player's mic picking up their speakers, because if they turn down their volume or shut off their mic temporarily, the echoing stops. 

I was assured by my voice chat library Normcore that this is a function of Meta's echo cancellation. 

Has anyone been having this issue recently or knows how to fix it?