It is working very well for me with rtsp://192.168.1.xx:554/Streaming/Channels/101 and authentication set to DIGEST. Although the camera is 2688x1520 (4MP), my Fire HD 10 can’t cope and the highest resolution it accepts is 1920x1080. I have set this as the camera’s main stream as the highest resolution in the camera’s sub-stream is 640x360. So I’ve dumbed-down my camera from 4MP to 2MP to use the Fire HD 10 - affects the quality of recording that I’m doing with Blue Iris using the main stream, but I’m not sure yet how much it bothers me.
It worked fine without Monocle Gateway, but I am using it ahead of the purchase of an Echo Show 5. The Fire HD 10 works fine with @tunnel.