Commentaire officiel
Solar noon is when the sun is at its highest point for the day at that location. That warning shows when Map Pilot Pro detects that the aircraft's shadow will be cast into the field of view of the camera which can cause sun hotspot issues.
https://support.dronesmadeeasy.com/hc/en-us/articles/360060320672-Sun-Hotspots
If the day is overcast you can safely ignore that warning. If you are using a circular polarizing filter to block the back reflection you can ignore it.