I've noticed that probably six months ago, vouching a comment would immediately return it to a live state ~90% of the time. Presumably because as soon as it hit

I've noticed that probably six months ago, vouching a comment would immediately return it to a live state ~90% of the time. Presumably because as soon as it hits the dead state it no longer gets flagged, so one is all that's needed to put it back over the threshold. Recently, my vouches have revived comments 0% of the time. I'm not sure if the algorithm or UI changed, or if I was simply using the feature too much for someone's liking and they disabled it for me on the back end? I've come across many, many helpful and thoughtful comments that I can't revive simply because this thing that should work has stopped even though I have about 30x the karma needed for it.