Update 5.22 has reversed the polarity of the thread mute feature, now making notifications explicitly opt-in.

This has the unfortunate side effect of ending notifications to all threads, requiring manual re-registering.

Except that the "Subscribe To This Thread" button keeps bouncing with "An error occurred, and we could not change the mute status of this thread. Please try again later."

Oh great. Let me look into that.
-- BK

You're seeing an error with the new Javascript not being loaded. Hold shift and hit the refresh button on your browser (if you're on a PC) and it'll hard refresh everything. On mobile, how to do a hard refresh vastly depends upon OS and browser, but that's what you'll need to do.

-- BK

Excellent, thank you!