The last entry in below image below indicates that there are two replies. Opening the topic this morning there is an opening post and a single follow up post.
Why did it state "2 replies" and not "1 reply"?
Could it be that your reply is also counted (just like with view)
No, I took the screenshot before I even started typing a reply.
A website admin may need to answer this, but would you see a reply notice for a spam post that later got deleted?