Just curious what the Channel Graph under Image Transmission should read when you have a good signal? There is never anything on mine so I'm just wondering if that means I have bad signal.

This signal graph is probably the most mis-understood element of the DJI GO 4 app.  But it is VERY useful.

The HD channel graph displays INTERFERENCE signal levels (NOT RC signal strength) on all available HD channels coming from devices such as WiFi routers, wireless phones, and baby monitors.  Thus, it is a GOOD thing to see NO signal levels on the graph, which means there is no signal interference on any of the available channels.  

In MY experience seeing NO interference signals is common when I have selected 5.8 GHz signal band, i.e., there is commonly (for me) no interfence on any of the 5.8 GHz HD channels.  On the other hand, when I have selected the 2.4 GHz band, there is interference at some level on almost all the available 2.4 GHz channels. That is why I almost always use 5.8 GHz HD transmission band in AUTO mode - both in urban and rural areas - it is the cleanest, most interference-free HD transmission signal band and I let the DJI GO 4 app choose the best frequency. Furthermore, when I have clear signal "line of sight" between the RC and the P4Pro aircraft, I can fly my Phantom 4 Pro out 4+ miles (25,000 feet) and still have at least 3 bars of HD video and RC signal strength.  In those rare situations when I do use the 2.4 GHz HD band, I choose CUSTOM mode and select the most interference-free channel (usually 13 or 20).

I thought I was having severe signal loss. Good to know that it's just my device causing the loss of image. Thank you.

Hi. Thank you for reaching DJI Forum. You may refer to this thread: https://forum.dji.com/thread-39021-1-1.html