some single keyboard keystrokes appear zero to five times (space, backspace are the worst)

Asseeninthe subject line and here, the space key often does not result in a single space being displayed although sometimes -- like just now -- it is termporarily starting to work. I am running FirefoxVersion 146.0.1 (64-bit)onWin11(andgetting erratic spaces and backspaces again.) Interestingly, the main Enter key also has similar problems although the keypad Enter key seldom does. TheDeletekeyhasneverhad this kind of problem so I haveoften used back-arrow and Delete instead of Backspace. Tobefair,thisalsohappenswithNotepad++ and other programs. I have no idea how to troubleshoot such an erratic/intermittent situation.