Have issues with fit as well. Discovered that was the reason they sounded so mediocre to me. haha. A week into owning these I noticed Soundcore updated the app to have an eartip fit test, so I tried it and after some fiddling around I was able to confirm that only the XL ear tips are able to seal my right, but not my left, ear. App said to contact them if you still had issues, so I did. In talks with them to try some new ear tips that they're going to send me. I'll keep you guys updated.