Many are having issues replying to posts in the Watch Beta forums. This has been reported aeveral times but so far it hasn't been fixed. While you can reply on a desktop you cannot while using your phone or even view the replies. There is a workaround. Log out of your Samsung account. View the beta forums and hit reply on a post you wish to comment. You can see any replies that have been made. You can type your reply and then when you submit you will be asked to login. After you login your reply gets posted. It is a ridiculous way to submit a reply but it appears to work. Then logout to look at the posts and its replies. Hopefully they will fix the forums once and for all.
