When I import a photo to Photoshop it moves around the workspace

Overscroll controls how much you can scroll when the document is at Fit on Screen magnification or lower.

When Overscroll is enabled, you can freely scroll/pan the canvas at any magnification, because the scroll bars are available even if the entire document fits within the screen. Overscroll can help move both a canvas and an open dialog box out of each other’s way, so that you can more clearly preview the effect of your changes while the dialog box is open. This tends to be more of a benefit on a large display, when you might prefer that a dialog box and the canvas under it are not both centered on the screen on top of each other if there is room to spread things out.

But if you never need to do that, you might not like how easy it is to slide the canvas around (like if you hold down the spacebar by accident, which activates the Hand tool), so in that case it’s better to disable Overscroll, which does not display scroll bars if the entire document fits within the screen. It locks the canvas to the center of the area not covered by panels, so you can’t “overscroll” past the document edge at Fit on Screen magnification or lower.

thank you - I think that did it

What is the purpose of overscroll?