[Gimp-user] Moving a rectangle to clone

[Gary Montalbine <gmontalbine cox net>]

I am using Gimp 2.8.14 in Mageia 5. I am using the rectangle clone tool 
to select an area in a photograph (.xcf file). I then use the move tool 
to place it in an area I want to overwrite. This is the procedure 
outlined in the manual. 
http://docs.gimp.org/2.8/en/gimp-using-selections.html. This is a 
procedure I have used many times. Suddenly it does not work. The move 
tool does not move my selection. It moves the whole image and the 
rectangle does not move. I would really like to get this to work. The 
paintbrush does not do a good job when a large area needs to be changed. 
Help greatly appreciated for a non tech type.
Gary