Singapore previously discouraged mask wearing. Only recently it mandated them, and now community transmission is plummeting. The resurgence in cases is only in migrant worker dormitories, where unfortunately 10-20 people share a room and it's extremely hard to prevent transmission. https://www.moh.gov.sg/news-highlights/details/38-more-cases...
I'm really not sure there is a causal link there between masks and cases, singapore is also doing extensive tracing and testing (except for their migrant workers it seems).
