Users unable to unmute and/ or start video on zoom in a breakout room

We hold a bigger zoom session in my office, and we like to hold our meetings in a breakout room. When bringing certain devices in that breakout room where we are holding our meetings, they are unable to start their video or unmute, it is like their device is frozen for them but are still able to hear. To resolve this issue, we have to have to move everyone back to the main session where they are able to unmute and start video. It becomes a big problem for us because we have to bring everyone back in that breakout room when we are done with that particular device. 

Has anyone had this issue before? and if so, was there a solution to this issue? 

thank you!!