This issue has been resolved and the service is operating normally.
The issue has been traced to elevated API error rates of a third-party provider. This may cause FlowView users intermittent issues loading appliance data within FlowView. The issue appears to be resolved at this point, but we will continue to monitor until we have confirmation from our provider.
Several reports of issues accessing Flow data per appliance. Summary pages not affected. The AppNeta Operations team is investigating and will provide updated status when available.