Have my 10, which gave only 0.2 increase from 8.92, but it's something, still. I see you put work in your comic (so +1 sub too), and I understand how it feels to have a rating drop in the blink of the eye and have no feedback on why it even happened. It leaves a lot of doubt. Was it legit dissatisfaction with an element of the comic or just troll exercising their "funny" bc there is no way to even pinpoint who gave the rating and what kind of rating it was.
I had this comic of mine to fall to below 5-6 at the start, and then I asked a friend to give a rating, it picked up, but later(like in a day or two) it dropped again even harder as if somebody felt it should stay where it is and not even gain a 1 point of rating back.
Considering it's my top comic on Tapas and doing pretty well, I don't think it's art or comic content and this beating rating down struck me just as somebody disliking the comic for some reason with vigilant passion... I did research as it turned out LGBT+ comics sometimes become targets of such rating bombs on Webtoon. Now it's on 9.25, so yeah, your rating may drop just because somebody is being an ***.
There other one had 10 score rating before idk for what exact reason it jumped in popularity. And it just dropped hard and then starting jumping up and down around 6-8 score mark. As if newcomers rate it only 1 or 10. However, after popularity dropped, it climbed to 9.61 - which pretty much is an example that no matter how hard you drop, if your comic finds its audience, and you do it well - you will get the sweet rating back.