Breakout Room Issue - Room Assignments Disappearing After Closing the Rooms

Hi there - since upgrading to the most up-to-date version of zoom on my mac - 5.9.3 (4239) - I've been having an issue with using the breakout room feature.

I will manually assign folks to breakout rooms, ask a discussion question, open the rooms, people will share, and then a few minutes later I'll close the rooms...... and then when I go to re-open the breakout rooms again after asking the second question, half of the people are no longer assigned to the room they were in! Disappearing breakout room assignments. Each time I close the rooms, half of the participants lose their breakout room assignment.

Is this happening to anyone else? Any suggestions about how to get zoom to stop doing this would be most appreciated!!! I've been using breakout rooms for years and never had this issue.