Unfortunately, this is a bug with Facebook itself. They updated the Facebook Comment plugin in June to have a new look. However, it appears that that change had some issues on mobile sites and they reverted to the 'old' version of the plugin in those views. That's described in this recent bug report:
developers.facebook.com/bugs/661910477277691/
The old plugin has a limitation that it will always show at 100px, which is another bug that Facebook has stated they won't fix:
developers.facebook.com/bugs/676913189022461/
developers.facebook.com/bugs/477133282433691/ (This bug report was created by me)
It's frustrating, but there's nothing we can do to fix the issue. If you're interested, feel free to create your own bug report about the issue. More reports can only help.
I hope that explains the issue, even if there's no good solution.
Thanks,
Alex
Mobile Comments
