Yes that is the line. It goes away if I hide the pano which seems to be the mountain backdrop.
I’ve tried shading rate 0.02, 0.1 and 1.0 and I think maybe 2.0, so I don’t think shading rate is causing that one.
I also see that line in the sunset promo, so it may just be an artifact of that object.
It’s not actually the top of the pano though, it seems to be somewhat below that.
I’m not that bothered, it’s such a lovely set.