Arrow keys stop working???

[Zackoon49]

So I'm one of those weirdos that are hopping onto this straight from FNF and my keys I usually use for that are:
- A and S on my left hand
- Up and Right on my right hand
But I was playing a custom song today, and for seemingly no reason, the game just stops reading inputs from my arrow keys!
I though maybe it was because I went off window to pause a video, cuz that's where it happened the first time, but then it happened for no reason MID SONG.
Any idea why this is happening and/or how I can stop it from happening???
(let it be known after further investigation, it is ROOTED from going off window, as doing that almost always breaks it)