Have you managed to use Big Blue Button with an /e/ phone? I tried with the native browser in listen only mode and it does not work (I hit the listen-only button but it does not disappear).
(I know some colleagues who use BBB on a GAndroid phone.)
As mentioned above, I tried to use the native /e/ browser.
When I try microphone mode, I get an error 1004 and
when I try listen only mode, the permission for microphone is asked (this is strange but I get the same on desktop with Firefox and it finally works as expected) then nothing happens…
With Firefox browser from /e/ app store BBB works.
I have tried to use BBB on Windows with Firefox, and it did not work, with the same behavior and error than with /e/ integrated Bromite. The error may be related to WebRTC. On Firefox/Linux it works perfectly.