The thing that is the most common and comes to mind first is that there is metal powder in the fluid and when it settled in the valve body over night it sticks the shift valve the next drive.
I would pull the pan and look close at the bottom of it purely for the information it gives.
If it were a broken second gear band or servo issue it would shift directly from 1st to 3rd.
The last one I saw do what yours is doing it would free up eventually and start shifting again but the next morning it was stuck again.
Turned out to be the rear planetary set needle bearings disintegrating.
