Make sure your pp3 load and save settings are compatible with your workflow. Mixing the save and load locations between cache and next to the image can make things tricky. For example, if you have a pp3 saved next to the image and you have the preferences set to save to cache and prefer loading from the pp3 next to the file, RawTherapee will save your edits to the cache but load the pp3 which does not contain the most recent edits.