Interesting. Have you made sure the guest user has all the updated permissions on the SF side to your public site home page and the objects on it?
Double check that the guest user profile has read permissions for the Skuid page object and any other objects on the page not accessed via your external data source. Also confirm that you’ve give the guest user access via sharing rule to the specific Skuid page record and any other records on the page not accessed via your external data source.
See this KB article: Troubleshooting: Guest User Access after Winter '21
