I think it has something to do with the language settings, for example I couldn’t see the comments on this thread, I logged in via the web version changed my settings to include Undetermined, English and my native language and now I can see the comments (both using the web app and Sync).

Hope that helps :)

PS: And in order to post this comment, I had to select explicitly that it is written in English…

PS2: Setting the language settigns also resolves the issue that OP reported initially.