Voice Crossing Between Two Players

Two players using the same IP Address - Player 1’s voice can be heard off and on through Player 2’s voice. Both players are in the same lobby. Only Player 1 is having the issue of being heard through Player 2’s mic. Any fix for this?

Problem is not the IP or channel they are in.
Both sit in the same room and and each of their microphones does record spoken word from the other person.

They need more space in their room or reduce what the microphone records.