Sorry to hear it! Could you take a video of you locking and unlocking Sesame 1) manually and 2) with the app? Please send the video or link (if over 15MB) to email@example.com We'd like to take a look to see what may be the issue.
It's possible that you just need to re-install Sesame. Make sure that Sesame is centered over your knob and that there are no gaps between the gripper and the knob - if there is, make sure to fill it with foam inserts or something similar so Sesame can properly turn the knob.
If it turns out to be a hardware issue with Sesame, we will issue a replacement under our 1-year warranty, but we will need the video to determine whether this is the case. Thank you! - CANDY HOUSE