Color Banding regulation Feature? (a6500)

[Workbank]

Hi,

Yesterday I wanted to test which color profile is best to use when you want to avoid banding in video footage.
Like expected slog3 had the most color banding.

So far, so good. The funny thing is that the banding is mostly only visible in the first second of the clip, after that it just fades away.
My theory is that the a6500 might have a build in regulation that detects color banding.

Does anybody knows something about that topic?
Help would be much appreciated!