Notebook extension main menu disabled

We’re building a Jupyterlab extension. One of its features allows the creation/managing of notebooks. Notebooks are opened under the extension context. I built that feature using the notebook-extension code under the packages’ directory. The toolbar commands within the notebook widget works like charm.
Everything works as it should but the Lab main menu. Most of the notebooks’ menu commands for the Edit, Run, and kernel are disabled
What could be the reason for this mapping failure between the main menu and notebooks opened within our extension while it still works for all notebooks opened using the Jupyterlab built-in file browser feature?

Thanks in advance!