This is quite normal - the ticket is hosted on Amadeus and ghost sectors are created on SABRE, and there are two of them due to the number of flights. If you said there was only one SABRE PNR then I would have been suspicious.

Normally you would use the AA app to update the PNRs, and that doesn't always work. BA isn't the only airline where this happens! But at check-in it will be fine. So long as the AA App doesn't show a Sync issue then I wouldn't expect a problem. This is contingent on there being no changes since the original booking, if there have been then AMEX should reissue or revalidate the ticket. So I think this is all OK from what I'm seeing here. The Amex side doesn't make much difference, but make sure you have their number handy just in case.