On Friday night 10PM (EST) Facebook users reported mysteriously being logged out when opening their mobile app. Users were met with a "session expired" message before being prompted to log back in.
In a statement to NewsNation late Friday night Facebook said they were aware of the issue and were quickly working to get it resolved.
Down Detector reported that 84% of Facebook issues were login related around 9:40PM EST Friday evening. There's been no explanation given for the widespread issue as of yet.