Originally Posted by
welshwiz
I have the same issue chose 3A/4A on BA MMB. Managed to change my seat to 1A on RJ but wasn't able to change my husband's seat to 2A so changed back to original allocation but wasn't able to do that on BA site or APP. In the meantime, I saw allocation of 1A and 4A on BA site but not on the seatmap (the two didn't match) and I wasn't able to switch back to original choice. Infact MMB wouldn't allow me to change to any seat I got an error message so I went back to RJ switched my seat back refreshed BA MMB and was finally back to square 1.
I had the same issue trying to change the seat of my travelling companion also - when I clicked on his name, all seats became unavailable even though he is also BA gold.
Fixed this by changing my seat first and then logging out of the booking. Then logging back in using HIS surname to choose a seat - all on the RJ website. Appreciate this may not work for you If you share a surname though!
I am now wondering if this in fact an 8F 777 with the front 2 rows unavailable since my route has no first, but the seatmap for the return was even more strange with rows 1, 3 and 4 missing on the BA app but visible on expertflyer and RJ.