I'm flying tomorrow and burned a RUC. It cleared at booking. Today I made a SDC to a later flight. The agent made the change but said the RUC wouldn't clear immediately, which I expected.
When I login to delta.dumb and look at my PNR, I see "Upgrade Status: Upgrade Waitlisted". When I click on "VIEW UPGRADE & STANDBY LIST" I see myself on the C+ upgrade list but not the FC upgrade list.
I see the same thing in the iOS app.
I called in and the agent said it's just a display issue and "you're definitely on the list."
Opinions on what will happen tomorrow? My guess is this will get straightened out at the gate.
You were in F via RUC, then SDC to Y? So long as F>0, you should already be in F. Call now and get the SDC fixed.