Something isn’t right here. “Waitlist” means you don’t have a seat. Partner awards can’t be waitlisted.

If everything appears correctly on UA’s side (status showing confirmed with an e-ticket number), then try getting in touch with BR to make sure it isn’t some website glitch. Though I will say that trying to reach BR by phone is virtually impossible.

If that doesn’t work, ask UA to investigate further, which might involve getting in touch with BR internally. It’s possible there’s been a communication breakdown between the two airlines’ systems.