enygy Loc: LI, NY

I shot this image today with my week old Tamron 150-600mm F/5-6.3
and noticed unusual horizontal banding in the background bokeh of this photo. This is the worst one. Not all but other photos show this effect as well.

This image was taken with a D610 handheld at 600mm, AF, manual exposure @1/400 sec, F/6.3, Auto ISO 2000.

I have never seen this effect before and am wondering what is the cause.
My guess is that it is the image stabilization system at work, or a defective lens?

Any suggestions are appreciated.

(Download)

SonyA580 Loc: FL in the winter & MN in the summer

I am thinking from the lack of comments that, like me, no one has seen this type of banding before. The only thing different I noticed going over the EXIF data was that "High Gain" was used somewhere in the process.

enygy Loc: LI, NY

Thanks for the response. I suspect the same as you. I've never seen this before.

I have no idea what "high gain" refers to. Nothing special was done to this using Apple Photos.

I have a message in to Tamron and am trying to tweak certain things. Will let you know.

JohnFrim Loc: Somewhere in the Great White North.

I don’t know how image stabilization would cause banding in the background without affecting the subject. I have images of people taken against a tiled wall that I think confused the stabilization, and my subjects had “ghosts” of themselves in the final image. I had some serious banding with some images from my first digital camera that I suspect was JPEG artifacts.