for the record , I don't usually gab this much.
BUT !!! I have found the solution.
Many moons ago , I was converting something to something else ( formats not relavant , or remembered ) I was getting an error that looked like it was a file access issue.
So , doing what seemed natural , I changed the properties on the calibre shortcut, under compatability , to "run as administrator"
That allowed the file to be converted.
fast forward to the beginning of this thread.
Going through what I had done , and racking my fragile brain, I finally went back to the properties for the shortcut and unchecked "run as administrator"
NOW , drag and drop works as it should.
this is one of those issues that happens about once every fourteenth blue moon , lol. but I certainly will NOT forget it.
When I was a support tech, I would have told the original poster ( yes , me , lol ) that there was a loose connection between the phone and the keyboard.