As I couldn't find any relevant Issue on Github, decided to check here first.
I can hear other non-GOS participants.
Other parties can see me and I can see them (camera works).
Also, non-GOS to non-GOS calls work fine, all permissions are in place.
It doesn't work on GOS A15 and A16.
Aside from GOS itself, other parts are quite similar (all devices are on the same VPN settings, etc.)
I do know mic is muted by default in EX.
Element X 25.06.2 on all devices.