I've noticed that when I run UBO with either Fanboy's Annoyance List or Social Blocking List, on the NasaSpaceFlight.com forums, the in-forum messageLike function is blocked.
Note that it's not an external social media button, twitter/facebook/etc.
I'm not familiar enough with filtering rules to figure out the culprit. There's no direct nasaspaceflight.com rules,so I assume it's something indirect. And it's a cosmetic filter (at least, when you disable cosmetic filters in UBO, without disabling the List entirely, it stops the problem.)
eg,
https://forum.nasaspaceflight.com/index.php?topic=43608.0