I have this issue on non stop flights (so no married segments, no layovers etc). GF shows identical prices for BA and AA (LHR-SJC; SJC-LHR premium economy) whether tried as RT or multicity. However when I try to book this on aa.com it fails over to the home page and then pulls up a higher fare. I can book this on BA but I wanted to burn some AA gift certificates

GRRR