Originally Posted by
acker
Try Malaysia Air website "Manage Booking"
Manage booking for selecting seats on IB. Odd but it worked for me. My MAD-BOS flight was booked using BA Avios. BA and IB wouldn't let me choose a seat. Malaysia Air let me. Go figure.
Thanks for this! I booked MAD-ORD using IB app, as I can't log-in via the website (argh!), but it errored when I tried to select seats. Your trick worked for me.