Realised it's useful if I post this here as well (from the Discord) to help the team investigate:

Regards to this: my group is finding that we lose the ability to hear/transmit on our radios with people who are within transmission range and definitely within network coverage. We lose connection with people who are few feet away from us but at long distances too. Communications become one way - so hear your team on a channel, but they can't hear you. It really does seem random in who it affects and what triggers it.

It's having an effect on keeping players on for long sessions who are getting frustrated with comms dropping in and out for no obvious cause or for new players who join private servers, speak up on radio but never get a response - not realising that they are bugged, not that they are being ignored.

For now, we are somewhat reliably able to fix the problem by getting affected players to turn their radios off and then on again - but it's a real bother in that you just cannot tell if you're not hearing a response because people just aren't responding/can't respond, or because they cannot hear you. Or thinking the comms are totally dead, not realising that you just aren't receiving the transmission (when you 100% should be).

We are having a very hard time determining what causes the problem, but we think we have pinned it down to only affecting receivers that are all inside the team's network coverage. Once you and your receiving/transmitting team get the "Out of Signal" text (but still within handheld/pack ranges of one another), the problem goes away it seems.

We tested by removing the ScriptedRadioComponent from all antennas (part of the radio relay prefab), disabling the SCR_RadioCoverageComponent from the ConflictBase and ConflictBase_MOB entities and it seemed to fix the problem by effectively forcing the whole scenario into an "out of signal" state - so that's what leads me to believe the problem exists in how radio von is being handled within network coverage.

It's a big concern that I hope the team can look into with some urgency.