Can only see the image at the top of screen and can't scroll down

[duane2000]

When I open a file I can only see a tiny strip of the  image at the top of screen and can't scroll down-or move it in any way. It does show the entire image in full screen mode but I need to switch back and forth between window a lot and I need it in standard screen mode. I've tried the usual, restarting, updating photoshop, to no avail. Any help? This is bizzare. I'm on a Imac and running Big Sur 11.2.3

thanks

[duane2000]

Now it's working, but I don't know what I did. Anyway, if anyone knows what's going on I would like to know in case it happens again.