I would try laying the quilt out on a spare bed or flat surface for a couple of days. I ordered a JRB Hudson River Hudson River L (20° F) in November 2022. When I received it I laid it out for a couple of hours and compared it's loft to my Katabatic Gear Flex 30° F TQ and found that it was significantly less lofty. I left it out for ~48 hours and it lofted up to my expectations. I purchased a $4 mesh laundry draw string bag for storage from Target for storage instead of the lower volume JRB vinyl storage package. Since then I have had no issues with loft.
I haven't tried this yet, great idea!


by the picks you showed looks like there's not enough down in it looks pretty flat!
I actually measured the weight with my cheap kitchen scale and it came out to 20.5oz so I think all the down is there, it's just not behaving nicely.


Quite possibly all of the above. Oh yeah, make sure you're hanging it right side up.
I always hang it green side out but I've even questioned myself as to if I was doing that wrong at one point!