This is likely due to the bounding 'cube' of the object leaving the area of the Construct 3 camera.
Currently the way to handle this is to use the ACE 'Set z height' to increase the size of the cube. Try a value around the height of your model divided by zScale. Experiment a little to find a good range. I don't know the size of your model, but start with 20 or so and go up/down. Let me know your results and if you need any more help.