FreeCAD has numerous functions behind alt+mouse1 combo, depending on context. When using it in KDE it creates problems, since immediately after alt+mouse1 click window resizes itself and is ready to be moved.

What I'm suggesting as a KDE fix is following: only move window after a 20ms delay AND drag. That would give FreeCAD time to capture mouse first, and would fix similar problems in other programs having functions behind that combo.

I'm aware that action can be easily remapped to meta+mouse1 for example, but making the window move operation not instant would make it work with defaults. And lack of good defaults is something KDE gets a lot of flack for.