Pinned pullout keeps scrolling back to the beginning

[harry-wg]

Bug Report

Current Behavior
Whenever I select a message from the pinned pullout, the correct message is displayed alongside the pullout. But the pullout immediately scrolls back to the top message instead of maintaining the pullout's correct vertical scroll position

Steps to Reproduce

1. Go to https://discuss.flarum.org/
2. Click on the first visible post
3. If the pinned pullout is not visible, open it and pin it
4. Still in the pinned pullout, scroll it down by a couple of screens
5. Click on a thread title in the pullout
6. Observe that the associated message is correctly displayed alongside the pullout
7. Error: observe that the thread title you clicked on is no longer visible -- the pullout has scrolled back to the top

Expected Behaviour
The behaviour in previous versions is correct -- ie, the pinned pullout does not scroll back to the top when selecting a thread from the pullout

Screenshots
You can optionally see the above steps in a video at [https://vimeo.com/505898276](https://vimeo.com/505898276

Environment

• Flarum version: As far as I can see, you don't mention this at https://discuss.flarum.org/ -- maybe you should?
• Website URL: as above
• Webserver: as above
• Hosting environment: as above
• PHP version: as above
• Browser: Firefox 85.0 64 bit in windows 10

[askvortsov1]

Fixed in #2402. Now we have an issue for it, thanks!