It might be because this week is x-server week, even if you didn't get to it. We didn't get extra packs for normal GNW either in S363-KonohaTeaParty. We had right research for normal GNW, but we did get extra packs last week. It does give the impression, that it would give extra packs on both weeks, if you don't get to x-server GNW. Maybe it's description should be rewritten to be more clear to players, that it gives extra packs for only 1 week even if it's active for 2 weeks?

It seems this is not a bug.

https://forum-narutoen.oasgames.com/page/show-post-35175-1.html

That page tells, how this thing works. We get extra packs for only 1 week of 2.