Accidental and Obscure Keyboard Problem and Fix, Right-Shift+E and a Stuck F12 Key

(We recommend you bookmark this blog. Trying to find helpful information in forums usually just ends in making you frustrated and angry. This blog does not speculate or guess. If we post it, we've tried it and it works. As with all our posts, if you don't care about the background info, you can head straight to the yellow highlighted sections for the problem and the fix.) Background I recently decided that, rather than upgrading my Linux Ubuntu OS for the umpteenth time, I would do a fresh (new) install of version 24.04. As usual, everything went well, except for one minor (actually MAJOR) keyboard problem I had immediately after booting up the new Ubuntu install: When trying to type a capital "E" using the Right-Shift key, I got nothing. I still was able to use the Left-Shift key + e to form my capital E, but I am an extremely high-volume writer and that solution is not sustainable long-term. What I Tried (aka, Useless Forums) Okay, based on my ultimate revelation...