Hi Juri,
This is what I got from Wolfram. Looks a bit invasive. I found a few work around, so I did not try
In bocca al lupo
Thank you for contacting Wolfram Technical Support. I understand the exponent keyboard shortcut is not working.
While I am having trouble reproducing the issue on my end, most common problems with Mathematica can be fixed by resetting it to its default configuration. This involves deleting or renaming some directories that contain the user preferences. Their location depends on what operating system you are running and on a Mac these are:
* /Library/Mathematica
* ~/Library/Mathematica
* ~/Library/Caches/Wolfram
* ~/Library/Wolfram
Some of these files may be hidden on your computer. You can navigate to hidden folders by opening the Finder application, pressing Command+Shift+G on your keyboard, and then typing the path to them (as ~/Library/Mathematica/ to open the Mathematica folder in ~/Library)
Further details on this process can be found here: https://support.wolfram.com/12464.
Please note that if you will be deleting these directories, you should back up any custom files you have saved to them. Mathematica will recreate these folders with the default files when it is started. You also might need to reactivate Mathematica after this procedure.
Please let me know if I have missed any part of the problem or if the issue persists.
