This bug has been around since AC9.
The first time you select the marker with the stretch command it should work fine. Subsequently to move the markers you first must click down and HOLD while doing this move the curser over to the move icon in the pet pallette and UP click. Now select the stretch icon and you can freely move the marker.
However, Door markers only move in and out in my experience and to move it laterally you have to alter it in the settings dialog.
Mac OS12.6 AC26 USA Silicon
M1 Macbook Pro