Alt + PrntScn + k doesn't seem to work for me anymore. (It worked the other day, not sure why it doesn't work any more.
) RaceCapture seems to keep auto restarting for me. I tried Ctrl + c but that doesn't seem to work either.So the workaround is I take the micro SD card and plug it into my Pi 4b, which won't run RaceCapture. Then I can install packages and make other adjustments, and then transfer the card back to the Pi 3b+. It's a kind of backwards workaround so I'm hoping there is some other option to kill the kivy app and prevent it from restarting. And yes, it restarts so quickly I can barely even type in the pi password before RaceCapture takes over the screen again.