Proximity Chat Not Working?

Hello fellow pirates! My friends and I are trying to sail the seas using Proximity Chat, but it is not working for us. The game is picking up our microphones, it even shows the green icon in the top right corner of the screen, but for some reason proximity chat isn't working. We don't have push to talk enabled or anything. It used to work just fine then one day it just stopped. I'm not sure what to do but I'm hoping other people know what to do.