Only 2 mobiles can connect to openfire meetings

hi all,

i have a really strange problem that i cant figure out

so i have it working great and my 2 mobiles using jitsi meet app can connect to eachother fine using the link, video/audio working fine

https://mydomain.com:7443/ofmeet/it

and then it opens up the jitsi meet app and i can see the other participant and vica versa

the problem is when i try to connect to the same room using my other mobile all video/audio go dead on all participant, they can only see themelves, only when i disconnect the session of the troubled mobile it starts working again

i have tried it with the affected mobile and another mobile, doesnt work

has anyone seen this strange behaviour

thanks,
rob