Hello I've bought two sets of C420s2. 

• Connecting the H200
  • I've connected the H200 to the internet via the RJ45 cable.
  • After adding it to the app it did a firmware update
  • Hub seems to work perfect

• I was able to connect Camera 1 to the Hub.
  • This one also did a firmware update.
  • The camera works perfect. 

• Next I tried to connect the camera 2 from set 1.
  • The hub does see the camera (correct mac address).
  • The hub starts blinking green and the camera also goes into syncing mode. (from red-green to a blinking green light).
  • But after a while the app gives the message that it couldn't make a connection. 

• Next I tried to connect camera 3 (camera 1 of the 2nd set)
  • The Hub connected and synced with the camera
  • It did NOT do a firmware update
  • The camera seems to work perfect

• Again tried the previous camera 2 (2nd from set 1)
  • again not able to connect
  • removed accu
  • did the reset with the interna reset button untii it quickly started blinking
  • Removed power from hub
  • disconnected rj45
  • powered on the hub
  • connected to the internet again with the rj45
  • tried to connect the camera again... 
  • no success

• Connected camera 4 (2nd camera of set 2)
  • directly connected
  • updated firmware
  • works correct

So it seems one of the four camera's has issues. Can you help me further?