The cam is ONVIF-compliant as is the NVR which is why, luckily, the video stream works....it's by chance the PTZ works through the NVR as you say and you're on a lucky streak because rarely does ONVIF compliance extend to successfully operating PTZ, audio, alarm I/O, etc. between a cam and an NVR of different manufacturers.
Again, since your Pro version of TC is a paid version I urge you to contact the developer via e-mail as I mentioned in post #3 and get his recommendation.