Another bug happens when setting the game/category with the Modify Channel Information endpoint, where it doesn’t update on Kraken.
It updates correctly on the Twitch page and dashboard, and in the Helix endpoints.
The same does not apply when setting the title from the same endpoint.
EDIT: This seems to be a more serious issue, since the Kraken API still isn’t showing the up-to-date game after now more than 4 hours since it was set.