viane

Well, I definitely tried gsap.set('.child', { xPercent: -50, yPercent: -50 }); at some point in my testing but that was the solution, thank you.

I've implemented the other recommendations too, appreciate the pointers. 

I have a line of code like this

gsap.to(this.$el, 0.5, { x: -bgOffset.x, y: -bgOffset.y, ease: Power2.easeOut });

In Chrome (Desktop and Mobile) GSAP does this 

style="transform-origin: 50% 50%; transform: translate(-50%, -50%) translate(18px, 3px);"

But Firefox mobile does this

style="transform-origin: 50% 50% 0px; transform: translate3d(0px, 0.9928px, 0px);"

Is there any way to force a consistency with the way this is handled?

See the Pen qBOLQPp by heyvian (@heyvian) on CodePen