Delta n United
 

Do what's going on with Delta and United?
I was jump seating on Delta a few days ago, and gate agent told United guy he can't jump seat on Delta, something about a memo that came out, looks to be a Delta ban on United and it's affiliates. She had to verify my airline before she would let me on. Unitef guy did get on, I think the capt went out and told them to board him.

Likely a delta connection flight by Skywest. Go look at those threads in either Skywest or United boards if you want an idea

Or Republic...

There’s a disagreement about the jumpseat between Mesa, Republic, and Skywest for United, ExpressJet, Air Wisconsin, and Commutair. Skywest, Republic, and Mesa now say there’s no valid reciprocal agreement between them and United plus those express carrier. Skywest and Republic fly for non United too to include Delta. If it was a mainline Delta flight, the gate agent didn’t fully understand the memo.

Yeah I had a gate try to deny me a JS a few days ago... and I don't even work for UA. Lot's of confusion going on, I'd say if you're UA then avoid any SKW metal for now, regardless of paint job.