At the bottom of a reply to a thread, if there is a reply to it, a button will appear formatted as “<number of replies> Replies”, but sometimes the counter is incorrect and shows more replies than there actually are.
For example: The button might say “2 Replies”, when clicking it shows only one.
@VSCPlays is correct, I am talking about the reply above that one. And no, the counter has not changed in the ~26 hours since this bug report was created
Here is a perfectly legible zoomed-out diagram with more arrows and red circles and exclamation marks to aid this investigation:
This happens when replies are moved out to a different thread. The thread you link contained more posts at some point but were moved out to a different thread.
We are not planning to address this as we don’t directly own the source code that the forum runs on (this is distributed by meta.discourse.org), and on top of that we don’t think this issue is impactful enough to warrant the engineering time we’d need to invest to fix it.