Trouble with Start Video Button

I was in a meeting the other day with my camera off. I wanted to turn my camera on for a little while, and I clicked the "Start Video" button. Nothing happened. I repeated clicked it and still nothing. The meeting participants could hear me, so the host did a "Ask to Start Video" request. When I accepted their request, my camera came on without a problem. The host said they never disabled my camera. Does anyone know why my Start Video button just wouldn't work for me?