@Gracehazel different numbering scheme.
There are no official global chapter numbers, only chapters inside a volume are numbered 1-12/13. That's why so far the translated chapters were numbered that way too.
But of course you can manually sum up the chapter counts for all volumes and find the global chapter number, and that's what SNSbu did. The downside is the "spoiler warning" showing up even though there isn't actually any gap.
109? Are you sure that's the correct number? I counted all the other chapters and I didn't find 108 but 104 (106 if I count Vol. 3 Ch. 9.5 and Vol. 4 Ch 0.