Why is Sugar they to load /rest/v11_5/metadata/public?type_filter=&platform=base&module_dependencies=1?

We upgraded from 8.0.2 to 9.0.3.

I upgraded the TEST instance and then upgraded the PROD instance.  The changes where committed to GITHUB using PROD.  Now after pulling the changes to TEST branch, it is broken.

The loading screen stays and when I inspect I see that sugar is trying to load /rest/v11_5/metadata/public?type_filter=&platform=base&module_dependencies=1

What could the problem be?