Ok, you are right TDW.
ONLY way to get rid of sextant window once for all is to clic back navigator sextant icon.
Clicking the little cross (up right sextant window) doesn't work (well it close the window but still re-appearing in any bino/UZO after)
Clicking deactivate sextant doesn't work either (still window coming back as reported above)
Not very natural imo

but the essential is to be able to close it definitely by the navigator icon!
Zoom levels are back fine.
I'm missing entries? Wich one exactly please?
So i'll add them in my french translate