Hi, thank you for your feedback.
Now I'm able to show the HUD correctly (even though with Visual Effects at Medium settings, no HDR).
Below is what I did, however I don't know if it was the root cause, but it works.
delete Output/preferences folder, to get x-plane default settings, and build my settings again from the beginning
delete Output/shadercache folder, to make x-plane compiles the cache again
My latest graphics settings with the working HUD.
Regards,