I am playing on 1.20.1 and I've noticed that maybe since I've last updated the mod, the Hyper invasion rarity doesn't take my config into account, even when I type /puresuffering sync gamerules in game.

I've tried having the hyper invasion happen every 4 invasions as seen on this screenshot. However after testing, I can affirm that they only happen every 12 invasions which is the default config IIRC.

I have tried deleting the puresuffering config folder then configuring and saving it again, but to no avail.

Thank you for reporting yet another issue, not many people take the time to report bugs like you have so I appreciate the assistance. I'll look into this asap and let you know what I find.

After further investigation, the changes to the "hyperInvasionRarity" config options only take place after the next hyper invasion occurs (I added documentation for the config option). If you find this not to be the case please let me know.
I could change the updating in the future to be immediate, however it would then require a rework of how invasions are chosen. I want to avoid any major game breaking changes until the next major update.