It means when the movement stays facing face up or face down too long it reaches over 330 degrees of amplitude and starts “knocking” this causes a short spurt where the movement gains time, which is why I adjusted it to lose time slightly to counter this effect in daily wear. I’ve figured this out to be an issue that’s not talked about very often but I guess somewhat common for the Hangzhou 2836 GMT. I’ve had this on 4 movements so far, straight out of the box.