So I already solved my issue by myself, but I want a better understanding of WHY it happened
Without manually defining the rotation order to YXZ on line 15, for some reason the inputs would only affect Y and Z, so if I did -30, 90, 0 the orientation of the camera would actually be 0, 90, -30 but if I then tried to flip it like 0, 90, -30 then the orientation of the camera would still come out as 0 , 90,-30
No matter what I did before changing the rotation type, I couldn't affect the X orientation angle
I honestly only solved my issue through sheer luck as I was messing with different things in hopes of finding the answer, but now that I know the answer I would like to further my understand by asking why I had this issue to begin with