I understand there is still no solution for this problem. I am having the same problem.
Playing on a PS4 pro, all the settings are correct. Two headphones with mics that work fine in other applications. Tried changing to NAT1 but no result.
Tried to work on a solution by changing the settings in the sp modem, no result.
Whatever I try, the voip symbol is not showing up behind the username. I can hear other players fine, just can’t reply, which takes so much gameplay out of the game.
The developers should be able to fix this? That would make this otherwise beautiful game even better.