Hello,
we did many projects with this accelerometer and it is really sensitive. So my guess is the configuration could be the issue.
Please see this project
It would be great if you share information how the device will be placed (orientation) and on which axes it will react.
Also take a look at the high-pass filter which filters “DC” value in the X,Y,Z axes. This way by enabling this filter you can rotate your device in any orientation and it only reacts to “difference”.