Hy Malte,
I think I found the problem! I followed your instructions and loading only the G3000/G5000 plugin, with the flight plan you indicated, everything worked perfectly. When I loaded the remaining plugins the NAV mode would not work again. Then I checked the Community folder and noticed that two versions of the Navigraph EFB charts app v1 had been installed, one was beta3 and the other beta7 (??) I deleted the two folders and uninstalled Navigraph HUB then reinstalled it and reloaded all the plugins and checked the community folder. It correctly reported only Navigraph EFB charts app v1 beta 3, and once the flight was loaded the NAV mode worked perfectly. I have no idea why two different versions of the plugin were loading. Thank you very much for your help!
Best regards
Max