The only other possibility that comes to mind is that System Events has a couple of ‘key’ commands which are no longer published in its dictionary because of the problems they can cause, but which still appear to work. They are key down and key up. If key down is used with shift, the shift key remains effectively pressed until the corresponding key up is issued or some kind of restart occurs.
tell application "System Events"
key down shift
keystroke "hello"
key up shift
end tell
If the key up isn’t issued for some reason — say, a run time error before it’s reached or the key up command not being in the code — it can cause havoc with the use of the keyboard until it’s corrected! Do any of your scripts contain uncancelled key down shift commands?
Interestingly, fooling around with this in Ventura, another way to cancel the effect with shift appears to be to transition from upper to lower case in the input text sequence:
tell application "System Events"
key down shift
keystroke "hello world"
keystroke "Hello world"
key up shift
end tell
Just as an additional data point, I do not have this issue on my Sequoia computer. Also, turning on the caps-lock key results in both hello-world strings being capitalized. With caps-lock off:
