I've noticed there is a new 'Same Here' button showing on any post (except your own posts).
I first thought it was a link to a similar question… Specially when the button just says 'Same here' without any badge value. But no, it is just similar to a like…
I guess the goal is to avoid and speed up instead of posting a reply or a comment 'Same here'.
Unfortunately, it is not possible to undo and no way to know who posted.
As your own posts do not show the button, does it mean you cannot know how many share the same issue than the one you posted ? If so, that's bizarre. Hope it will show the counter at least when it is non zero.
Let me see how many 'Same here' on this post… .