Local History is an absolutely fundamental/crucial feature of Jetbrains IDE families - including Pycharm. Why would it be missing for the .ipynb files? Here is the right click/context menu - in which the Show History is missing:
In addition: the Code Editing History Navigation feature is not working in the notebooks: notice that the Last Edit Location option is disabled even though I had edited this notebook:
Why are basic/core code editing features missing for these notebooks? Is there a way to enable them?

