I don’t think you’ve done anything wrong, there’s a similar issue now for France ex-T5 and APIS/the app doesn’t cover it...
Any French resident travelling on a Brit passport who has a round trip originating in France has to show their CDS (residency permit) to the appropriate BA staff member before trying to get through conformance on their way to their flight home.
I think it’s a fairly recent change, I got clobbered by it for the first time early this summer and it’s a PITA…..
No doubt an attempt by BA ensure compliance with the Schengen 90/180 rule, but I do wonder if any other airline is doing similar.
Last edited by wiggy; 15th Aug 2023 at 11:25.