In 22.214.171.124 (I think this is unique but I cannot be certain) if I do not have autostretch enabled, it sometimes occurs that I cannot stretch the image on screen using the button on the window, or move the slider either in the histogram tab. If I tab back to the prior image in the sequence, it works, as it then does if I tab forward again to the image that previously refused to stretch. Here, I close a plate solve window and try and stretch the last image. It refuses. I load another image and it stretches ok. I close the problem image, re-load it and it can stretch.
Video showing behavior. Hope this helps