Seat selection Flying Blue award flight on Garuda
I have an Economy award ticket booked with FB miles, and I received KLM booking code (with 074 e-tkt number).
The flights are AMS-SIN on KLM and SIN-CGK on Garuda Indonesia.
I could select my seat on KLM AMS-SIN on KLM website (interestingly it first asked 25 EUR for seat selection upon booking, as I am currently a statusless FB peasant. But when managing my booking few days later, I could select a seat for free).
Selecting GA SIN-CGK is not possible on KLM website, referring me to contact the operating carrier.
I could enter the booking code on GA website, it shows my chosen seat for KLM AMS-SIN but got unable to choose on GA SIN-CGK.
The error reads "There is an error with one of the special service (15235)" with all seats shown as not available. What gives?