What guests see offline
Phones lose signal at events. A Board never shows an old version as if it were current.
While it’s current
The foot of the Board says when the last change was, like “Updated 11:02”, beside the Board’s address. If a check runs late, it says how long ago it checked: “checked 25s ago”.
When it can’t check
If the phone has no connection, the foot says “Offline · showing 11:04”. If the phone is online but CueDuck didn’t answer, it says “Can’t reach CueDuck · showing 11:04”. Either way it keeps the last version it had and stops any countdown it can’t confirm. When the connection comes back, it catches up by itself.