Calibration shapes have different location after saving and reloading a Cura 3mf project file #149

I do not know if this is a plug-in issue or Cura project file issue:

Cura 5.4.0 (Linux Mint Cinnamon)
Calibration Shapes 2.2.4
I add two shapes (cylinders) to use as supports for my model
Repositioned and resized them as needed.
Save the Cura project as 3mf
Open the 3mf project (as project--assumed from here forward)
Cylinders have moved (on Y axis -10mm towards center of bed / "0" position)

Tried using "lock model" on the XYZ position for the cylinders.
--It does not prevent them from being moved in the Cura session by typing in new coordinates
-- It does prevent them from being dragged with the GUI Axes arrows (This may be just how Cura is)
--When 3mf is saved and re-opened, cylinders are not locked anymore

Tried moving one cylinder Y+10mm from desired location (further away from "0")
Saved 3mf
Opened 3mf. That cylinder is now in the desired location -- ie it still moved -10mm)

Created a new cylinder.
Did not resize it.
Relocated it from 0,0,0 to -20, 20, 0
saved 3mf
opened 3mf
Cylinder is now at -20, 10, 0

QED. Thanks.