WYBOT Robotic Pool Cleaner - Osprey 700 (Open Box)

I was excited to receive my Osprey 700 robot. I put it in and after 90 minutes it picks up hardly anything and it's time to charge it again. It's not worth the effort or money for the tiny amount of debris that it picks up. I kept thinking I was doing something wrong but I did what the slim instructions said. It's cute and well-built but for me, it's a waste of money. It's easier to sweep the floor then vacuum than to keep charging and putting this in the pool. My inground, vinyl liner pool is 40X18 and 7 ft deep. I have a Betta robot that skims the top of the pool and it has worked perfectly for a few years and it cost almost half of what I paid. It is not built as well as the Osprey (the 700 is heavy) but it picks up debris and that's the point. I'm checking to see if I can return it after using it 6 times. The only reason I used it that many times was hoping I was doing something wrong and it would get better.