If this is showing online then the issue is between the hub and Tempest. If doing what @eric said and a long press on the Tempest button to reset it doesn’t allow the hub to see it, then the issue may only be with the Tempest.
Sorry. I did not see your response with all my computers disconnected. I disconnected everything again and set up the dedicated router again. Removed all stations visible. Re added station. Pushed button on tempest as directed. Does not find it. Removed apps from other two phones. Removed and re added stations. Does not find it. Reinstalled app and added station. Reset everything. Does not find it. Now what. Rebox to send in?
Definitely open a support ticket using the above link.
at this moment your hub shows offline … but if you start it and it shows online, most probably the Tempest has an issue.
That we can’t see nor help much here but open a support ticket. They will contact asap (they are swamped … we just reached 10K online stations and as many help requests 
)
They will double check with you and send you a new Tempest to replace the one that won’t work as expected.
Right. I went back and reinstalled the single router. I deleted all apps from all three phones. Then deleted all stations. Did the long press on the tempest. Went back into the app and could not find the tempest. deleted the station. Tried again. Nothing. Then tried setting up with a new email and the tempest would not connect to that account either. Unfortunately, the hub does not appear to connect at all now. I have had the home internet off too long now for family happiness so will have to try and reconnect hub again later. Will put in support ticket for replacement. Thanks for all the help! Boxed up again for replacement. Congratulations on the 10,000 units!