Do you have a bigger one maybe? I've had non of the issues you describe. Pack it as full as you can and tighten everything, pull the side/top straps through the saddle rails
I've got the 13L one, and sometimes fill it to absolute capacity. Looking at your photo, I might have been putting it on wrong...I've never put the top straps through the saddle rails.
Do you have a bigger one maybe? I've had non of the issues you describe. Pack it as full as you can and tighten everything, pull the side/top straps through the saddle rails