How to mine it now? Is it "v9" or what? The first post and even official website say the algo is "CryptoNote v7", pools reject all shares with all the algos I've tried so far.

The new algo is a twist of CNv2, you've got to choose it with your miner. I use JCE CN GPU 0.33B16 with "variation 21" setting. Mining on
https://stellite.miner.rocks/ pool.
It's power hungry, around 100W more than CN heavy with my GPUs.
Seems no block found after the fork yet, explorer says block is 503001