I have an RPU applied for a flight from SAN to EWR and EWR to PIT tomorrow. The RPU cleared on booking for the EWR to PIT leg. However the SAN to EWR hasnt cleared and looking at the seatmap on the app tells me that no there are no F seats open ( I don't know how much to trust this info)

I am pretty sure that I can clear a CPU on the EWR to PIT flight if no RPU were applied and tbh i don't really care about an upgrade on that flight.

Assuming that my RPU doesn't clear on the SAN-EWR flight, I don't want to throw away my RPU on my EWR-PIT flight. What are the possibilities of my RPU clearing on the SAN-EWR flight and if there isn't when should i call in and recall the RPU?

FYI, Its a red eye tomorrow
Thanks