Wait it got azed at 11??? I’m so sad that it got axed so early the characters are well written so far and like you said the world building is great
If I must guess, Ain Soph's made the mistake of fashioning itself a story with "vampires"...in Jump SQ, while Seraph of the End is still around. This factor is especially bad because whatever we may think of Seraph's quality, that series still has a pretty ardent native fanbase whose readers will keep buying and voting for it. For them, other "vampire" series are the easiest target to
not vote for.
That aside, with Jump+ now being such a strong web-based platform, a more traditional monthly publication like Jump SQ is not the most bountiful grounds to grow one's success. These days, you need impact of the likes of Dark Gathering and The Bugle Call in order to survive and develop into an outstanding mainstay.