Hi Anh,
Unfortunately accepting answers as reply feature cannot be disabled on selected category. It can only be disabled globally by disabling the Q&A under Settings>General>General Features or by applying the restriction to certain usergroups in the ACL section(http://take.ms/e3Vi7).

I've disabled that feature but still see the "Accept as Answer" button for a demo post I made?

I tried creating a new post in case it was because my original test had been created prior to me changing the global config but doeesn't seem to have an effect.

Hello Simon,

Hm, when you turn off the Q&A feature, regardless if the post was created before or after changing the settings, the "Accept as answer" should never show up.

Could you please start a new ticket so that I can look into this for you?

Of course, will do.

Thanks Simon!