That’s clear example how dangerous it is to have strictly centalized software delivery. Why not using foss mirroring servers? Or releasing updates as torrents? It would be much more resilient to possible single server failure.
Of course, then NC-team would loose that “preferential treatment” power, deciding who gets new/updated sw first, who later, and who much-more later (like now: >2 month after nc20.x declared “stable” and proudly released, yet many users still did not get this update)…
Before i reported here, the issue had been visible for a few days.
Apparently the distribution server can fail, publish invalid update info or inconsistent info without being noticed or acted on.