I understand that crappie are very light sensitive. The brighter the sun, the deeper they go , depending on the clarity of the water. I have had some similiar experiences with the bright sun and I have moved up into a creek that has a lot of shade or moved to the other side of the lake or river where more shade is and continued to catch fish. Not to say that this will work every time, crappie are a lot like our wives-----you never what kind of a mood they are in that day.
Jim