Opposing the sex industry is a common and principled left stance. It is only in capitalist countries where their cops are funded to harrass people and Johns are rarely punished where there has been a need for a "sex work is work" movement.

In countries run or established by communists, they were often facing racial or otherwise imperialist systemic rape ("comfort women" for Japanese imperialists, for example), recognized how this worked in both slavery and "transactional" capacities, and correctly banned it. Things like erotica were swept up in this total purge of marketing sex, and enforcement is inconsistent as it is usually regional.

Please so your best to educate yourself, be accurate in your summaries, and to not be sinophobic.