Lag time getting into breakout rooms

I've hosted meetings with breakout rooms, and one attendee remained in the main meeting for up to a minute while everyone else was sent to their assigned breakout room. Is there any way to force them into the room or speed the process? I've been in Zoom meetings where breakout rooms failed and some folks never got put into their room. I'd like to have some tools/resources on hand should that occur in my next meeting. It causes anxiety for the long person who remains in the main room while their breakout room group is likely getting started on the activity.