@JasonAS,

 I will have to look specifically into what the limitation is but it has to do with the different quality streams that are available to the camera. I believe that the camera can handle 2? HQ video streams - This is the same reason that you cannot use an SD Card alongside an NVR - as they will both want to look at the main HQ stream.

I would recommend taking a look at this FAQ as it will probably fill in a few missing pieces of info for you, such as the two different RTSP streams, HQ and LQ.

This line in particular, makes it appear that Tapo Care and a Local Storage Method (SD or NVR) will use the two streams. 

"If the Camera is inserted microSD card and subscribed Tapo Care, its RTSP stream will fail. You need to remove microSD card or cancel Tapo Care to get its RTSP stream."

You could change the quality stream on the NVR as I think this will prevent the conflict, but I am not positive. If the behavior is sporadic, it may only be happening while events are being recorded to the Tapo Cloud, or your NVR connectivity may be intermittent/cutting out?