tahrenholz wrote: Can you help me understand what's going on here?
Welcome to FreeCAD and the forum.
Which version of FreeCAD are you using ? On which Operating System ?Read here
how to obtain and provide this info.
I am asking because your description sounds like you are running 0.16.6704 which had several bugs and one of them was
a behaviour like you describe. In that case I would recommend de-installing , and downloading and installing of 0.16.6706.