Old QTI 1.2 test resources and Onyx QTI 2.1 resources are not automatically converted to the new format. For QTI 1.2 tests this is already possible, but the option is a bit hidden in the editor. For Onyx QTI 2.1 resources it can be done manually by exporting and re-importing as new resources. During the import the resources is recognized as QTI 2.1 and will get the new resource type.
It would make live simpler to have a convert button for old test resources directly in the test menu of the learning resource.