It may be true that RMS needs a certain level of signal to fill up the graph. This may be a difficult question, but what is the threshold?
Also, within the 18-22th timespan, there are gaps where there should be values. For example, in a 18-19th timespan, I can hover over a graph at 09:20 on the 18th and see a -69dBm signal, but that specific point is not shown in the 18-22th timespan. This does not seem righ - please check.
Thank you