That would be the reason. You have to actively play and touch all your structures to prevent them from being deleted.
If it has been a few weeks it may already be too long to restore them now (backups can only be kept for so long due to their sheer size of the backups).
Wait for an admin to respond. Maybe you get lucky…
Next time, if you aren’t going to play for so long, you need to use the “Keep Structures (Holiday)” donation package, or just accept that they will be gone when you return.
As a addon: on starte system, they get deleted aftee a time no matter what, so always focus on get out of there. After that, you must touch your structures every 14 days…
Personal Wipe Counter means that each player in the Starter System (planet + orbit) has 14 days for their spawned structures. Each player and each structure independently (personal).
Type cb:wipe in the game chat to see the upcoming wipe times!
It’s easy if you check your cb:wipe counter regularly (and of course only on the Starter Planets + their Orbits). It does not count for all the other playfields!