Same problem, and fixes are only temporary. I've tried to open a JPG using Photos Legacy, but here's an additional issue that may point to the real problem: if you right-click the JPG file and click "Open with", Explorer freezes and has to be force-closed. So there is no way to change the default action from within Explorer.
SO... I went into Settings, "Default Apps", and changed the default for both Photo viewer and JPG files, to "Photos Legacy." That worked, and now after two days, it's still working!🤞Just have to remember not to click on "Open with".