I'm running macOS Mojave, and I'm getting strange behavior from my Shift key.
After I've typed in any text in the terminal, if I press and release the Shift key, it will add
;2D;10D to the end of that string. For example, if I type
hello and immediately press and release Shift after, it will become
hello;2D;10D, and it will add that additional string as many times as I press and release Shift, e.g. pressing Shift twice at the end of
hello would create
hello;2D;10D;2D;10D, etc. If I have not typed in any text yet and press and release Shift nothing happens.
When I am in Vim Insert Mode, or in colon command mode, if I have typed anything, pressing and releasing the Shift key moves my cursor to right after the first character of that recently created string of characters. For example, I press
i to enter Insert Mode.
| represents my cursor. If I type in
hello and press and release Shift immediately after, my cursor ends up here
h|ello. I noticed that in Normal Mode, when I press and release Shift, the bottom right corner that displays your key press combinations quickly flashes
To debug, I have removed all my plugins and commented out my .vimrc file, and I am still getting the same behavior. This behavior occurs in any terminal emulator I've used (the standard Mac terminal, iTerm2, VSCode command line, etc.) I don't get this behavior outside of the command line, e.g. when I use Microsoft Word, or even typing this now, pressing and releasing the Shift key has no effect. Any feedback on why this may be occurring would help!