it may depend on the surface you have him on... holland lops seem a bit more sensitive to that, at least compared to my lionhead. for example, my lop can't stand the slippery tile in part of my house; the lionhead couldn't care less.
when I first got them (at 8 wks for the lop/7 for the lionhead), I noticed the lop didn't ever seem to hop much whereas the lionhead hopped tons. at the time, they were always confined to either their cage (which had an inch or so of bedding on the floor) or their outdoor pen (an inch or two of grass to move through).
once I got an all-purpose tarp to put beneath their cage, put a big pen around the cage and started leaving the side door open so they'd have more room to play, she was suddenly hopping fairly often across the tarp - unlike other surfaces, it wasn't slick and didn't have grass/bedding sticking up higher than the actual ground/floor.
holland lop babies seem awfully low to the ground when standing, so it makes sense she'd have more trouble moving around in grass/bedding because it came up to her tummy.