Box have taken steps to resolve this issue. All services have been restored and they are now considering the issue to be fully resolved.
We apologise for the inconvenience this may have caused.
Box are currently investigating an ongoing issue affecting latency in Box.com, Box Drive, Box Notes, Box Sync and Box API. Logging in and accessing content may also be impacted. For further information please see https://status.box.com/incidents/44ysgpnblprd