In a test #matrix / #element setup via containers when I am trying to make a call via "Element X" app I am getting "MISSING_MATRIX_RTC_FOCUS" error. Any tips? #devops #sysadmin

UPDATE: seems the initial problem was about firewall, now only one user from mobile can start a call, the other users on browser has the button grayed out.

FIXED: final missing part

```
"features": {
"feature_group_calls": true,
"feature_element_call_video_rooms": true
},
```