Limit to motion tween position ?

Hi all,

I'm having issues moving a symbol using a motion tween in Animate CC

I have created a long symbol (height of about 8000 pixels) scrolling from the bottom to the top across a 1920x1080 canvas.

At some point, I can't move the symbol any further, it's as if there's a limit to how far up I can move the symbol with the motion tween.

If I import the symbol in the scene without the motion tween, I can move it anywhere. So I assume the issue is the motion tween.

Is there a limit to positioning with a motion tween?

Can I get a workaround or a tip on this ?

Thanks