[Zahrim]

I am unable to see the full image during the lock screen slide show. There is no option in the slide show for lock screen on how to size the images, it to fit.

Yes they are custom images I would like not to alter them. windows photo player sizes them properly during a slide show.

The restart did not help. The background change altered only background, not slide show.

[interlocutor1980]

You are using your own images in the slide show or windows default? If you are using your own images in slide show then try to select images according to your screen resolution...

Act you are right that there are not much settings available regarding Lock Screen.

Also try to restart your graphic driver.
To restart graphics driver manually, you can use the keyboard shortcut Win + Ctrl + Shift + B. You shall notice that the screen starts flickering, there is a beep and everything is back to normal.

I hope your problem will be solved...

[interlocutor1980]

Also Open Personalization then Background here you see an option "Choose a fit for you desktop Image" Choose "Fill" Option...

[Zahrim]

So far nothing has fixed this issue, the pictures still will not fit to the screen