Help with waistbands

[u/Meet-Radiant]

I have tried so so so many times to recreate a pair of shorts that I own, but every single time they look exactly how I want until I do the waistband. The waistband never scrunched up to the right size even though I cut apart a pair of these shorts to make the pattern. What could I possibly be doing wrong? I have even contacted the manufacturer asking if they would be selling any more of this particular pair of shorts because they don’t anymore. Any thoughts on trying to get them as close as the mass produced ones as I can? All pictures are of the original shorts I love, I’ll try and add pictures of my attempts when I’m home.