Unable to add Product Page Optimization

After attempting to add:

We can't process your request.

The new test will show up with a status of "draft". If I try and "Edit details of Product Page Test" and add treatments there, the "Save" button does nothing.

If you look in this forum you will see there are several threads about same error in different sections of App Store Connect.

Unable to add Product Page Optimization
 
 
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