This has been going on for a couple months at least, but not much longer than that.
I have images set to open with paint.net (basically a ghetto version of photoshop, but free). Used to be if I select multiple images on the desktop or some folder and hit enter, each would open in its own tab in paint.net; but lately doing so is just setting them as a slideshow style desktop background. Desktop background is typically just a single image - slideshow is not enabled, but it turns itself on every time this image fuckery happens.
Any thoughts on how to get it back to normal?


Have you tried ensuring that paint.net is your default program for all of the various image file types? That might have something to do with it.
What’s your process for opening… are you holding the ctrl key and left clicking all of the images you want to open to select them, then right clicking one of the selected images and hitting open?