I’ve had a hard time following this particular thread, so please accept my apologies if this doesn’t answer your specific question.

It sounds like you made a change to a ticketed award reservation and you’re seeing the message saying that your flight is now waitlisted.

The first thing you should do is find both your old and new ticket number. Your old ticket number would be on your original receipt. Your new ticket number would be on your new receipt, but if you didn’t get a new receipt, you can generate one from your itinerary. If your ticket numbers are the same, stop here: you’ve identified the problem, and you need to call UA and ask them to reissue the ticket. If they cannot reissue the ticket, that’s an indication that you do not have a valid reservation and you should ask if they can put you on a UA-operated flight to SFO. (It’s unlikely that they’ll be able to restore your original ticket, but you can ask).

If your two ticket numbers are different, that’s great. Next, go to EVA’s site and look for your ticket number. (If you don’t see your ticket number on EVA’s site, you’ll need to call). Make sure it matches the new ticket number, not the old one. If it matches the new one, and the status in EVA’s system shows confirmed — you’re all set, and it doesn’t matter if UA thinks it’s waitlisted. If the ticket numbers match, but EVA’s system has old information — that’s bad, and you’ll need to try to get UA to fix it (but there’s a good chance they won’t be able to). If they have your old ticket number, you have two choices: (a) try to get UA to re-push the ticket, or (b) call EVA, explain the situation, and ask if they will let you read them the new ticket number so they can pull it from their side.

If EVA does not have the new ticket number, you wil almost certainly not be able to board.

Good luck, and I hope this helps.