There is no "follow" or "unfollow" button on either Firefox or Chrome on my Mac using OS 10.13.6. They do appear on my iPad iOS 11.4.1.
Please paste a screenshot of where you expect the button to be present
I think you have a browser plug-in which is blocking these buttons from appearing. I suggest you disable the plug-ins one at a time to figure out which one it is.
Customer support service by UserEcho