Why do my 3 recordings today, each have a different screen size?

[BeeeGeee]

I recorded 3 sessions on zoom today. Each one shows the screen recording as a different size or dimension.

The first one shows a really small video image, and is surrounded by a wide black frame area, on all 4 sides. 

The 2nd one is still framed in black all the way around, but the frame is much narrower.

The 3rd recording has no black frame at all, the image covers the full dimensions of the screen. That's what I'd like to see on all 3 videos! But I have no idea why this is the only one that fills the screen shot.

What's going on? How do I control this? I see no camera dimensions setting in my account. Nor does my iMac (it's new to me) have camera settings for dimensions (that I can find).

I'd like to have the video image fill the screen every time, and not have wide black frame all around it at all. It's especially disconcerting that the first one, which was the group class session, is such a small screen in the replay. 

It's after 1am and I've been at this for hours, nothing seems to work. Please help, thanks! 

[Adele_K]

Hello! I have the same problem. Join to your request. It was easier when I installed earlier version. But now it's not allowable.