On cloud 2fa is enabled, on forum it is not. New account creation without verification is quite simple with this forum. There is also no captcha to prevent bots from posting.

Tp-link, do you want to hire pro developers to solve this problem for you or did you already give up and enjoy promotion for prostitution? If prostitution posts are that frequent, you should make this forum 18+ in case you gave up.

Due to prostitution promotion users on this forum suffer as it seems like that all restrictions which you tried failed, beside the fact that it does not happen since few days, it was happening before I joined here.

If all of this is complex for tplink and you have no solution, seek for help or find appropriate hosting company which would help you to resolve it with success.

Accounts with lets say lower level than 1, can have restrictions, all prostitution post come from new accounts. There is so many ways to resolve it. I suggest to tplink to open StackExchange channel, there will be no prostitution and no spam.