The second Chrome browser does not show the remote video from the Firefox source.
I tried the same scenario but without the forceH264=true so VP8 codec is used.
In the VP8 case it could take about 5-30 seconds till the second remote video from Firefox starts to flow.
If Safari or Chrome is used instead of Firefox in the above scenarios then everything works fine.
mediasoup and mediasoup-client provide lot of debugging capabilities for the application developer to check what happens. If you use them and encounter a real bug or issue, it’s ok to report it. However, just telling that the online demo app does not work in certain scenarios is not the way to go.
I’m just sharing my observations. It turned out that the issue is related to the simulcast feature. If simulcast is disabled with simulcast=false in the URL params then the issue is gone.
Also I ran everything on my dev machine. I checked the mediasoup server log. If Firefox is using simulcast then the log contains:
The SRTP decrypt error is legit since FF does not (yet) support RTX so it just resends the original media packet when mediasoup sends a NACK to it. If the packet arrives in disorder after mediasoup sent the NACK, SRTP decrypt will fail for the second one since the original one was already received.
BTW I cannot reproduce the issue but I do know that Firefox does not behave very well in bad network scenarios.