Thanks for letting us know about this, and I apologize for my delayed response. This seems to be an issue only with updating Geekbench 3. It should still be possible to download Geekbench 3 from the Purchases menu of your App Store profile. In this case, you will likely need to uninstall the Geekbench 3 application, and then install it again through the Purchases menu.
Please let me know if you run into any further issues and I would be happy to take a closer look.