Issues with users getting stuck in breakouts

We have issue with switching participants from one room to another room. 

Below is the scenario,

3 -Participants and 1-Invigilator(Host) :

The Invigilator has created 3 waiting rooms and moved participants from one room to other room. At this step, one of the participant was stuck & froze. And this participant also disappeared from the investigator's list.

But, At participant screen there is a black colored screen with processing icon (Attaching the reference)

We did perform testing with multiple scenarios & participants but observed the same issue over and over again.

Please Note, There was no network issue and performance was also good. 

Thanks,

Pranath