After a few days it looks like the tightness of the bag on one side looks loose

[Thea]

Please keep in mind: UMAi Dry NOT a vacuum bag. It allows for both moisture and oxygen exchange. Air pockets post zero risk. Toss out any expectations that it should behave like a vacuum bag.
Also, because the UMAi Dry membrane takes up the gooey moisture coating on the meat, it relaxes, and always looks a little loose a day or two after bagging.
Untuck that extra plastic from under the meat. It will block air flow.
UMAi Dry is designed to be a single layer protective membrane. With good air flow to all surfaces, aging in a regularly used modern frost free kitchen refrigerator located in a room temperature environment, you are ensured consistent, safe dry aging. .