Board Thread:General Discussion/@comment-2212553-20150907145116/@comment-17725354-20150907150418

I wouldn't think Wikia automatically signs you in cross-devices (they would have trouble verifying you are the actual owner of the account), but I don't know. I rarely use Wikia on a mobile device.

Either way, you should send that and the Facebook bug in via Special:Contact/bug so Wikia staff will see it.