I don’t know exactly “what is going on”, but I have a bit of information that might help guide your research into the issue.
SuiteCRM v8 shows some modules in “legacy view”, others in the new Angular UI. This is configurable. You can see which one you’re getting by just paying attention to the graphics, they’re different.
The new view doesn’t have Edit views and Detail views. It has a single view for both purposes, called “Record view”. But I don’t know how the Studio views map to these. I wouldn’t be surprised if the stuff used from Studio was only one of the two views (Edit/Detail), the other one being completely ignored.