Updating a nodeType while a repository is active will not work unless the repository is shutdown and restarted again. I believe once the nodeTypeCache is populated, updates to the same type will never be seen.

Scenario:

session.workspace().getNodeTypeManager().registerNodeTypes(<initial cnd>, true);

with the CND being:

[test:nodeTypeA]
- fieldA (STRING)

and then subsequently updated with:

[test:nodeTypeA]
- fieldA (STRING)
- fieldB (STRING)

will cause a CVE when updating a node of type "nodeTypeA" in the same session. I believe I have found the culprit, pull request forthcoming.