I managed to reproduce the problem.
To describe the problem slightly differently:
The state of the flag "render orbits for moons" is not included in the Cel URL.
(and I fear there may be other render flags which are missing.
)
To reproduce the problem:
Select the menu option Render / View Options / Orbits / Moons
view the moon's orbit path
save that url to a file
select the url
The moon's orbit path continues to be drawn
de-select the menu option Render / View Options / Orbits / Moons
the moon's orbit path is not drawn
select the url
the moon's orbit path is still *not* drawn.
It should be.