It looks like the camera is too far forward. Try moving it back and rebalance. I had a similar problem which was sorted by rebalancing. Try balancing the tilt first, with the camera pointing straight down, using the slider on the motor. Once it points straight down, move the camera backwards/forwards til it sits level. I had a similar problem where the tilt motor did the same. It was down to a front heavy camera (GH4, Sigma 10-2o, Speedbooster). The motor would hold it for a short time and then "give up". If you do the above and it still does it, it might be a faulty motor/encoder.
Peter Parker got a reaction from Axel in My Review of the Zhiyun Crane 3-Axis Gimbal