Show notes does not have a shortcut key assigned to it as far as I know. Your screen shot even shows that it does not have one. Does using CTRL & S bring up the notes on your system? Because on mine it only opens the save dialog box.
The underlined S in both Show Notes, and Save, means when I hit alt+f for File, and then S, it doesn’t do anything, because they’re both set to S. I don’t mean the ctrl+s shortcut.
I’ve removed the ‘shortcut’ for the Show Notes feature so it doesn’t interfere with Save.
Thank you, sir.