@tanukihat
the reason why this Spider manga only has less than 20 pages per month : because the artist , かかし朝浩 , Kakashi Asahiro , is working on some one-shot henta* , and on another 2 on-going manga-s right now :
https://www.amazon.co.jp/%E3%83%97%E3%83%AA%E3%83%B3%E3%82%BB%E3%82%B9%E3%82%B3%E3%83%8D%E3%82%AF%E3%83%88-Re-Dive-1-%E3%82%B5%E3%82%A4%E3%82%B3%E3%83%9F/dp/4065092574 .
https://www.amazon.co.jp/狼は眠らない-(1)-角川コミックス・エース-新川-権兵衛-ebook/dp/B07VDHQ9Z2/
maybe he only writes the story for the 2 manga-s Princess Connect! Retar* : Dive , and The Wolf Won't Sleep , but they still consume his time .
i guess the publisher of Spider manga is also responsible : in the contract , they only want less than 20 pages per month , so they dont pay the mangaka too much , and they dont push him to draw more pages . the mangaka has too much free time so he works on another 2 manga-s .
https://web-ace.jp/youngaceup . on this website , most of the manga-s also have less than 20 pages per month , so this is the policy of the publisher , not the fault of the mangaka .
also note that Spider manga and The Wolf Won't Sleep manga have the same publisher : young ace up . so that means young ace up asked Kakashi Asahiro to work on 2 different manga-s at the same time .
https://web-ace.jp/youngaceup/contents/1000013/
https://web-ace.jp/youngaceup/contents/1000116/
also , this chapter is late because the artist was working on the tankoubon volume 8 or something .