Never noticed this behavior before. In AI I have a simple closed path made up of four anchor points forming the shape of a rectangle with two rouned corners. The path has a stroke but fill=='no print'. When I copy and paste into ID from AI the stroke is outlined and I have a filled compound with the stroke value burnt in. How can I get the stroked path into ID so I can stroke width emains editable? ( I know I can add a stroke to fatten the comppound shape but that will not thin it unless object is over a plain colour background)
Copying and pasting from Illustrator to InDesign or vice versa is problematic because it's not designed to be done that way.
Either prepare your shape in Illustrator, save it, and use File>Place and choose your file and place it in InDesign.
Or prepare the shape in InDesign - indesign can round 1 or more corners.