F5ing while holding a part in EVA Construction wont be there on F9ing
GOG KSP 1.11.0 (no mods, no dlcs)
Screenshots Showing Issue:
Before: The Battery is on the side of the rover
Holding Part and Pressing F5 (Quick Save): The Battery is held and moveable by the mouse pointer
On using F9: The Battery is gone.
The easiest fix here is probably disable Quick Saving when in EVA Construction mode
with a message like, 'Exit EVA Construction to Quick Save'
Disabling the menu to avoid manual saving was a good call, but Quick Save bypasses that.