GOES 16 sun glint.
I noticed considerable (a sensor over loading) area of sun glint on GOES 16 in the Pacific off South America on March 6 around 19:00 and for quite a period afterwards.
The Sun on Saturday was around 5 degrees south of the equator.
Geostationary satellites do show some sun glint when the sun is at and around 0 degrees.
But MSG-4 was only showing a very small sign on Saturday.
Difference in sunshield design?