after constantly having zoom freezing I just uninstalled and reinstalled it but now it is saying that I am in a meeting (I'm not) so all the buttons are greyed out (see screenshot). I'm guessing the solution has something to do with force ending all calls but I'm not on any? How can I do this?

I'm a person who has a video conference with Zoom every day.
But there was a problem with the video a few days ago.
The camera in the device has been checked through another app to see if it is working, and access is also turned on in the camera settings.
But when I use video on Zoom, I don't see any alert pop-ups, I don't see myself, I only see a black screen. The camera lights up.
I've tried deleting and reinstalling zoom a few times, but it still doesn't work.
I'm really uncomfortable during the meeting, so I'm looking forward to your help.

I do a monthly Zoom where the focus is on a 99 year old class advisor "Les". He's mentally very sharp but not a techie and his vision is failing. There are often 40+ people on the Zoom. When someone speaks, Les has a hard time identifying who is talking as he scans the multiple screens to find the talker. As a result, he misses the beginning of the conversation.

What's the best way to have the current speaker's video prominently on-screen so Les doesn't have to look through multiple pages of participants? Ideally, Les' video would always be on-screen but its ok if that's not easy.

Thanks,