I've noticed some changes on the seat selection under Manage My Booking.

For some weeks after the Amadeus upgrade the seat selection would stay when you select from the iOS app even though it shows as pending seat charges. That stopped working recently.

Now for my upcoming booking coming up in a week, the 2 outgoing sectors now showing as "Free of charge" for seat selection, but oddly the return legs 2 days later are chargeable, all sectors have the same booking class.

Just another of the strange ongoings on MH's site.