When calling from FusionPBX 1 to a conference in FusionPBX 3, using FusionPBX 2 as a transit, the image of the transmitting device is freeze. How to fix this problem?
I can add a wiring diagram
I would make sure all the codecs are a direct match including the in transit box. I would then try a new client (Jitsi used to have known issues). Also why are you using the transit box? Freeswitch does not make a great proxy.