I have to go to the pump they are on, log in, and unfollow from there.
This happened with the "fortune" account on jpope's instance (it was cool and all jpope, but... ;-) )
I can reproduce the problem, but cannot reproduce the workaround (or at least, not in every instance, not every time).
I am firstname.lastname@example.org
I was following email@example.com , and "Stop following" button does not work. I logged in e14n.com and then can unfollow Evan (and follow again).
I was following firstname.lastname@example.org , and "Stop following" button does not work. I logged in microca.st and then... it shows "follow" button in Zack's page (and it does not toggle).
I decided to follow email@example.com, and then, I cannot unfollow him either.
The same happens with firstname.lastname@example.org
But it works with email@example.com
Then I played a little bit (went to my "followers" page, clicked here and there) and now I cannot unfollow nor evan nor jpope.
I logged out from all the sites (didn't close the browser).
I went then to https://fmrl.me/jasonriedy , logged in, and followed firstname.lastname@example.org. Now I cannot unfollow him, even logging out and logging in again in fmrl.me, it shows the "follow" button and nothing happens when I click it.
I don't know what else to do in order to help to reproduce the problem/workaround. Hope it helps.
I'm pretty sure this is a dupe of #518