XF 1.2 Post Orders getting scrambled


Active member
As of late, some threads on our forum are having the post orders get scrambled. Checking the post dates shows that these posts are in the 'proper' order chronologically, but clearly not the order they were actually posted in. This has also only seemed to happen after rebuilding thread information.

I'm guessing it might be an add on issue, but I have no idea where to start with debugging something like this as it seems almost random.

Wondering if anyone else has run into this problem or has any insight on where to start with solving it.