Crop tool issue

Having a problem with the crop tool, when I select crop the handles and grid are showing but do not respond when I try and use them to crop.  If I swap back to another photo and back again the crop box has moved to my previous attempt which failed and I can then use the crop tool as normal.  This issue is sometimes intermittent but happens more often than not.  Only just started happening and I have updated to latest version but still happening.  Probably something I have done but struggling to figure it out.  Any suggestions? Thanks!