I understand you could create a sample separated project that reproduces the issue (i.e., doesn't call the token builder?)
In that case can you send the sample project? Without us being able to debug it's hard to tell what's going on.
@wlandgraf is there a point I could break point to see where the decision might be made not to call the token builder?
First of all, what HTTP requests do you see happening from the browser? You see all the flow happening, the call to authorize endpoint, the call to token endpoint...?