Workaround: Add a page above the page you want to show/hide based on a URL variable. Page Logic based on URL variables will work on any other page in the survey other than Page 1. The best thing to have on this page is a welcome message/instructional text!
This should just be a temporary workaround, we will work to fix this one up quickly.
Thank you so much for your patience while we resolved this issue! Page Logic based on URL Variables is now working, any workarounds you were using can now be abandoned.