Can you mount junction boxes with cable going up instead of down?

So I’ve got my junction boxes to mount my bullet cameras.
The wires come down from the roof so can I have the wire entry at the top facing up?
On the box itself it says up is the other way with cables going downwards?

Would having the entry hole of the junction box upwards be a problem or does the wire have to go in from below?
I’d just turn it upside down? Or is it to do with water getting in?

Thanks.