Issues with android devices

Sometimes we have users try to connect to our Jitsi server using the app on an android device. However instead of connecting with their intended meeting, they get sent to an empty room. My typical fix is to have the user remove the app, reboot the device and connect using the web which is successful most of the time.
My question is , is this a problem on the server, the app or a bandwidth issue?

Thank you for all help and replies!