I am a Oneworld Sapphire status member and will be flying from Tokyo to Europe on JAL next year. The flight number is actually displayed as a codeshare with Iberia (and with an IB flight number) but operated on a JAL aircraft. JAL has said they cannot access the seat map for my flight as it is an Iberia codeshare booking which prevents me/JAL from selecting specific seats or even seeing the seat map. Iberia has said the flight is on a JAL aircraft so JAL needs to provide the seat selection. I have now been sent around in circles between the 2 OneWorld carriers and all without success or resolution. As a customer, I thought the point of OneWorld was to provide seamless travel.

​​​​​I am also flying out to Tokyo via Helsinki on a JL flight number but operated by Finnair aircraft and have been able to select a seat on the Finnair aircraft without any issue. Why is JAL so difficult as a OneWorld partner and is this a known issue? Thanks