After several days and just after send my last post, i found the answer.
The problem that i detected its that the SIDS and STARs for some airports had gone, so I try to found a reason for that, and finally I found a solution.
The first problem its that the reason of the SIDs and STARs was a corrupted file called “content.xml” found here:
C:\Users(USER)\AppData\Local\Packages\Microsoft.FlightSimulator_8wekyb3d8bbwe\LocalCache
Now you have to do this:
Remove Navigraph AIRAC using NavData NavCenter. Delete Content.xml. Restart sim. Confirm you see correct NavData using default NavBlue Database. Shut down sim. Reinstall NG AIRAC using NavData NavCenter. Restart sim and confirm you’re seeing NavData (try outside US as that’s where NG really shines).
With all this done, the stutters are gone, and the SIDs and STARs are back.
Kind regards, I spect that this info will be usefull for someone with the same problem!