When I select something in a large drawing, it will move.  I'm not clicking and dragging the entity.

Example:  I have a rectangle, and I click to select two of the sides.  The endpoints and center point of each of the lines are identified.  When I move my mouse, the lines I selected will move and drop to where I stop the mouse.  I did NOT click and drag them, I have just selected them and then moved my mouse to select something else on the screen and the selection will move.  And the endpoints and center points are no longer identified, like the move is over (that I did not initiate) and it is ready for my next command.

This is a very large plant layout drawing, about 150,000 KB.  I'm not sure if that is adding to my issues or not.

Any insight would be helpful.  Thanks!