Cities not protected from decay

[Deantwo]

And again. I don't log in for a few days and come back to 6 cities decaying. One of which I repaired last time.

So it is at least the same cities that decay?
And you are sure that solar system is in your Land? And with the correct name?
Is the avatar with the solar system on its Land in some form of limbo?
What does the city reports say? Decay from Abandonment while the city has population?