When my failing test fails, the TCCL is:

ResourceDelegatingBundleClassLoader{bundle=org.apache.cxf.cxf-rt-transports-http [109],parent=BundleClassLoader{bundle=org.ops4j.pax.web.pax-web-jetty [225],parent=null}}

And the reason constraint failing is an @DecimalMin. I think I see how to make a failing small test case.