The equivalent of the fix proposed in Q921 has been integrated in the current version at https://github.com/ThingPulse/esp8266-weather-station-color/blob/master/esp8266-weather-station-color.ino#L442 with commit #2133809.
Is the reported illumination correct? You're not in the southern hemisphere, are you? Maybe you hack together a small test sketch that iterates through the illumination values and renders the matching moon icon to see if the order made sense to you?
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