For a while now, AFF won’t let me comment on any fics? Or rather, the square for writing the comment in just isn’t there?

I don’t think it’s just me, because I read a story that’s updated fairly often and that has lot of subscribers, and it usually got a lotttt of comments on each chapter, but now it always just says “no comments”? 

Does anyone know how to remedy this? I don’t think it’s the authors who has activated something, because it’s on every single story I visit. I want to thank the authors for their stories and cheer them on! Feels a bit rude somehow to just read and not leave a comment :/