I looked around and didn't see a post about it elsewhere, but the Romero Post Mortem achievement awarded under Forums and not under Achievements for me. I posted a screenshot of it below.

SPOILER (click to toggle)

Appreciate that you looked, but on the first page of threads, there's a topic right under yours with "Romero Post Mortem" in the name. Sidebar events show in incorrect category

(which might also be a duplicate. this specific issue has been reported multiple times in the last couple months.)

(ps number 2- just pretend this is a staff post okay I forgot to check the box T_T)