I've not been able to test on an actual phone, but one thing I did notice viewing in FF RD mode, it did take a while for the content to "pop up".
I'm guessing there is maybe an
onload event to trigger that, so on a slow connection you have a bit of a wait before seeing any content.
If that be the case:-
(a) Have a little patience and wait for the content to turn up.
(b) Consider what this does for UX/bounce rate, having to wait for actual content is a big turn off for users.