That weird quirk happened to me too Nettie a few nights back.
I was all set to record a pre-dawn -3mag event and just
minutes before the event I rechecked my time and elevation etc...
only to find it gone from the Heavens Above list for the next 24 hrs.
I refreshed, rechecked, checked my location etc...it was gone.
Still captured the event, it is in the terrestrial section.
As Ron says, it happens
Steve