Filter by user + Scrollbar interaction

To Repro:

  1. Go to Topic List Previews

  2. Filter by someone’s posts, effect easier to see if you filter by someone with less posts eg

  1. Go to the bottom and open “n hidden replies”. If you filtered by the above user it’d be 436 hidden replies at the time of writing.

  2. Scroll up some amount using the discourse scrollbar, the topic “reloads” and closes the previously opened replies.