Video & Mic failure after transfer from breakout room

[SamWLBR]

We had a speaker prep call that happened in a breakout room while the meeting is in progress. The speaker had full video and audio in the breakout room.  Did nothing and re-entered the meeting automatically when breakout room was closed, but the video and audio was not available.  The functionality was locked when the speaker was in the main meeting (ie the video and audio button were not able to be pressed and activated when I clicked on them) and the issue was not solved even the speaker logged out and rejoin the meeting. Why would that happened and what went wrong during the virtual room transition?