Pinned conversations not collapsing

I have a few conversations pinned and I’d like to keep them collapsed so I can better view the recent conversations. But every time I perform an action that updates something on the site (e.g., send a new message, delete an old conversation, switch conversations, etc) the collapsed Pinned section expands again.

(NB: I’m using an old version of Chrome because I’m still on Windows 7, so if you can’t reproduce this bug it’s fine to consider me an edge case)