Consider:
ACS Chemical Biology
ACS Infectious Diseases
These get renamed to:
AC Chem. Biology
AC Infect. Dis.
Seems the S is being dropped.
I would also prefer it to say ACS Chem. Biol..
I'm not sure of the differences in logic, but it's being returned correctly here: https://marcinwrochna.github.io/abbrevIso/