Just noticed some recent changes in #LCSH terms. The headings "Transgender people" and "Transsexuals" have been replaced by "Trans people", and "Transsexualism" has been replaced by "Transness".
Depending on vendor, your library catalog may have automatically made these changes, or you might need to make manual changes. Also, because "Transsexuals" was a term separate from "Transgender people" beforehand, your system might not have auto-replaced both with "Trans people", so it's worth checking.