I've been copying/pasting settings for years. Starting a few days ago settings are no longer pasting to the target photo. The progress bar in the top left appears as if they're copying over, but nothing happens -- the photo stays unedited/raw. This is a brand new problem. Anyone else experiencing this?
There are two ongoing bug reports for what may be two different bugs. Let's figure out which one you're tripping over.
After you observe this behavior, take one of the problem photos into Develop -- have the sliders changed position to correspond with what you pasted, and is the photo in Develop reflecting those changes?