Everything works but not video webkit to Firefox

[TheDanielMoli]

If there are only Chrome or Safari participants, everything is ok. If there are only Firefox participants, everything is ok. If webkit (Chrome or Safari) and Firefox users are mixed, everything looks fine on the webkit browser, while Firefox is stuck on "waiting for video". The issue happens only when using ConfBridge. Calling between Firefox and webkit works fine, StreamEcho works fine (well, of course).

I am using Asterisk 16.7.0 on Ubuntu 19.10 and running the tests with all peers from localhost, on a Mac. I am using a stun server but not a turn.

confbridge.conf

[general]

[default_bridge]
type=bridge
video_mode=sfu

[default_user]
type=user
music_on_hold_when_empty=yes
music_on_hold_class=default
dsp_drop_silence=yes
denoise=yes

extensions.conf

exten => video_conference,1,Answer()
same => n,ConfBridge(guest)
same => n,Hangup()

pjsip.conf

[guest]
type=endpoint
context=default
direct_media=no
allow=!all,opus,ulaw,vp8,h264
aors=guest
max_audio_streams=30
max_video_streams=30
webrtc=yes
dtls_auto_generate_cert=yes

Am I doing something wrong or is this an Asterisk issue?