Stinky Ubbi Diaper Pail

We’ve been using our Ubbi Diaper Pail for 17 months now and oh my gosh, it smells so bad. At first it was great.....It doesn’t do a great job at containing the smell now though! I’m really disappointed in this product! Does anyone else have this issue? Is there something I can do to make it better? I let it air out from time to time over night outside, I’ve wiped the inside down with vinegar as well as other cleaning products and I’ve sprayed the inside with air freshener. Nothing seems to help.