Are you talking about the very top of the pack with the zip pockets or the pouch towards the bottom? I know this might be obvious, I think you're talking about the top but when you use the word pouch it makes me think of the open compartment on the bottom...Anyways, I used this pack over the weekend running around the canyons of Escalante and didn't have this issue. I was skeptical of the hex-nut lock at first but there are two attachment points and if you go for the one closer to the top of the pack it makes the load more secure if you're not totally loaded up... Try that out. I didn't have it come loose on me at all or experience any flopping. You might want to try a different packing strategy out instead of trying a new pack. I have yet to find a daypack that worked as well as this Fluid, and I've tried many.

If you want to really go nuts there's a third loop for the hex lock at the very top by the carry handle. I think the second one will solve your problem though. The only thing about the hex attachment is that you kind of have to give it your attention as opposed to a standard clip that is kind of an automatic action every person who uses backpacks has a muscle memory for.

Never had a problem with the hex nut. Thought it was gimmicky when I bought it, but now I love it.