The bedroll
is a tight fit. Indeed, such a tight fit that I can't pull mine out again!
Looking at it, though, it does look as if it goes in at a slight angle; there is a gap underneath the bedroll tab, when seen from underneath:
If no other bedroll will go in, either, you could try soaking both the bedroll and the orange part of the backpack in very hot (but not boiling!) water for maybe 10 seconds, so that the plastic softens a bit. That could make the parts more agreeable about going together.