EF mount Sigma 35mm 1.4 Art strangeness when adapted to R5

My Sigma 35 Art must need a firmware update. At least I hope it's that easily fixed.
When I tried it on my R5 using a Canon RF control-ring adapter, I get these two dark concentric circles near the edges of the frame. They show in the viewfinder at all apertures, but only show up on the image exposure at f/1.4, 1.6 and 1.8. At f/2 and above they are gone from the recorded image, but still marring what I see in the viewfinder.
Anyone else out there with an R5 and the Sigma 35 Art seeing this?

Here's what it looks like at f/1.4 (and that exif info is not reporting correctly, this WAS shot with the Sigma 35)

Known issue. Turn off lens corrections. It's not an 'R' thing, happens on earlier DSLRs too.

https://www.diyphotogr​aphy.net …enses-newer-canon-bodies/

That took care of it, many thanks!