Saving and reopening (simple) new extension shows undefined properties

[bytesinmotion]

I just created a new extension. Just basic infos and created one Domain object with two properties.
Saving works fine and database definition all is ok.

Now I load it in the extensionBuilder and the two properties I defined show up as "undefined" and are empty.
Saving of course gives error. I tried to reenter the values for the properties. Saved, reopened. Same problem.

Tried with "typo3-12-reactjs" and with "v12-load-old-extensions" - same problem

Attached the simple definition

ExtensionBuilder.json

[PKuhlmay]

Thank you, I am currently on it as I needed to refactor the extension loading. This should be solved soon.