Exact same situation here. I was able to claim from the sale page but not game page, game page kept throwing errors/not showing purchase button
Viewing post in Grok?! 1e - Zine Edition comments
Sorry for the difficulty - I just updated the game price itself to PWYW, so hopefully others don't have the same issue.
I also just dropped the free Grok?! 2e Quickstart Guide.
If you like what you find, please consider following the Grok?! 2e Kickstarter!