There is. Lemmy.ml is currently shadowbanning kbin for unknown reasons.

Lemmy.ml is blocking the bots kbin uses for federation. The devs have ignored anyone asking why. It’s been weeks and only applies to Lemmy.ml, so it appears to be intentional. They’re running slightly different code on their flagship site than what all the other instances use (which makes me wonder what else Lemmy.ml has changed compared to what’s publicly available).