When I use Lens Correction on a photo from my EOS 6D MKII & EF24-70 F2.8L MKII lens, under geometric distortion correction it seems to introduce some odd artifacts on one edge of the photo - lines similar to a bar code if I don't tick the edge extension box. Only happens with the 6D MKII, not if I use my older 6D with the same lens.
Incidentally the profile shown for both combinations is EOS 5D MKII + EF24-70 F2.8L MKII
Any ideas what is causing this and why only with files from the 6D MKII only and how to fix it??