thank you for your response, i’m another admin of this site. Unfortunately your instructions didn’t help us to fix this issue(. We are using Flex Mag theme (or it’s child theme, to be specific) (Flex Mag - Responsive WordPress News Theme by MVPThemes | ThemeForest) Our theme is loading WordPress comments template and we can see comments which are created by standard wordpress instruments: http://joxi.ru/EA4WBJ9sDVEvY2. We used Health Check, as you said but it’s didn’t help us find out what may cause this issue. We still see no comments with default 2016 theme and discourse (as the only active plugin).