Hi,
I was “lucky” to encounter the same problem twice in a row on Xbox, when MSFS was released on console, and I quickly realized the low level of reliability of the product. As long as this kind of problem has not happened to you, you can keep your illusions, but the later it happens to you, the stronger your resentment will be.
As @Its502GeekGuy said and if it can cheer you up, know that you’re not alone. Many threads about this issue:
- Logbook lost/deleted after shutdown of xbox servers connection
- XBOX version logbook issues
- Lost all “progress”
- Playtime gone missing [Packages out of date]
I agree 
, that’s the correct term to qualify this bug. 