Long-time lurker but first post in a long time. I hope the more experienced members here can shed some light on this issue.

Just back from CDG-ZRH-JFK on Swiss metal in first class with a full-fare ticket issued on United stock. (It priced out the same on both Swiss and UA but I needed the PQDs).

On the outbound trip, I used FC lounges both at JFK and ZRH.

On the return, I was denied entry to an almost empty FC lounge by the lounge attendant and manager. Both said I was ineligible to use the FC lounge because the tickets were on UA stock, not Swiss.

The Senator Lounge was packed and there wasn't even anyplace to sit (yes, first world problems abound) and I even tried the Panorama Lounge in Terminal E, which was packed solid.

Has this or a similar circumstance happened to anyone else? I'm *A Gold if that matters, although it probably shouldn't.

Upon arrival, Swiss personnel at JFK told me that there was nothing in the rule book that should have resulted in my being denied access to the FC lounge in ZRH.

Thanks in advance for your wisdom and advice.