The first two times I used the self-serve kiosk the machine complained constantly about unexpected stuff, and I noticed that I had placed my bags up to the edge

The first two times I used the self-serve kiosk the machine complained constantly about unexpected stuff, and I noticed that I had placed my bags up to the edge of the platform. Now I place them in the middle of the platform and the machine seems happy. Either that or the store adjusted the sensitivity on the machines, hope that helps.