Incorrect ZED2 disparity and depth

I am using the ZED2 Explorer to capture stereo images (H.264 lossless png). When viewing the shift between left and right images (disparity) I see that distant objects (more than 20 m away) have negative shift/disparity compared to closer objects.
I also observe that the depth computed from the disparity is incorrect, even for closer objects (less than 5 m). Depth is computed using:
Depth = Baseline(120mm) * Focal length (pixels) / disparity (pixels)

Are these issues due to uncalibrated camera? Does the camera need to be calibrated?

Hello and thank you for reaching out to us,

The camera needs to be calibrated indeed, but we do factory calibrations before shipping them. You can make a manual calibration with our tool ZED_Calibration, or restore the factory calibration with ZED_Explorer.

Also, can you provide a SVO of what you describe ? And maybe tell me in what conditions it was taken (temperature, etc.)