kde is a window manager and desktop manager. in that case go to the control center and look around the window configuratio. not sure where exactly it is as i don’t use that (bloated) kde but you should find it. simply unmap whatever command grabs that shortcut and you should be fine.
Hi, try pressing shift with the usual combination. eg. [ALT] Right click will be [SHIFT] [ALT] Right Click.
This sorted my problems with selecting loop edges.