Photo viewer Slideshow not working - both versions

Hi, I am trying to find a slideshow that works on Windows 10, with no luck.

First I tried the new Windows 10 photo viewer. Clicking slideshow on this app works, but only for a single photo. Clicking on any logical key, like the arrow keys or space bar or mouse just ends the slideshow. I would expect you could enter the slideshow and then key through all your photos.

Giving up on that, I launched the old Windows Photo Viewer. Launching slideshow in this trusty old program made all my photos appear the wrong size. They were too big and the bottom of the photo went off the screen so that I was only seeing about 80% of the photo.

Please help me fix one or both of these issues please!

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