The little "friends currently playing" icon next to games in the library isn't showing up

[DarkACB]

Apologies for the unclear title, I really don't know what to call that little icon

example (credit to u/UosaYT on Reddit):
https://preview.redd.it/49a8m5lwg7n31.png?auto=webp&s=1dd055b38feb6312783e7f76815a61af67628e9f

For some reason, even though I have friends currently playing games in my library, the icon doesn't appear. I know they aren't marked as private, because it shows them playing on my friends list.

This only started happening yesterday, before which I was away from home. I did use Steam on my Chromebook and laptop while I was away, so maybe that broke it. Idr if it was happening on there as well.