So apparently, the Trigger only works on the map screen.
I'm not sure how I would go about it from here. I have tried manually triggering the QTB Arrow Moving as a Common Event in battle instead of relying on the Switch, which does move the arrow slightly, but it immediately freezes after a few frames. Not sure why.
If I put it under the Loop instead, it begins looping upon itself before it is able to complete the QTB Arrow Moving event, which makes the arrow go haywire.
I hope you will be able to come up with something, perhaps trying it yourself in a battle screen might give you some more information and context? I'm very thankful that you've made this script, it works wonderfully on the map screen and very much appreciate your assistance for this issue!