@Aido Hello

We could help look into unstable issue further and try to fix it, can you help confirm some case details:

For ' when 2 or more cams are installed to the recent connection outage for video stream.' is there any Error message on tapo APP at that moment, may I have a photo? 

If your camera is unstable, make sure the camera is receiving a good signal by checking the signal strength of the camera on the APP:
 Tapo APP, go to device  settings->click the name of the device ->signal strength (You could tap on the Wi-Fi icon to see the value of the RSSI:

(-40d- 68dBm is good/ average, less than -68dBm is relatively poor : relocate camera or router to get stronger signal)

Make sure camera connects to main router directly, not through AP or extenders. 
Also Confirm Camera firmware and Tapo APP version are up-to-date