I believe part of the problem is your code is not able to load the package-info.class to read the @XmlSchema annotation when the JAXBContext is being created where-as this works just fine from our test suite. FWiW, having Envers add the namespace does not fix the issue either.

If the @XmlSchema annotation is detected properly, you'll notice under standard execution, the call to XsiTypeLoader::parseXsiType is never called; hence the difference between standard execution and your code thus far.