Fyi - this is nothing new with seat maps when flights are controlled by another airline. At around T-48hrs, AF/KL takes over flights so you can't view or make changes to seats in the app.

Also whenever there are irops and rebookings, you can pretty much forget the app to work properly. Make sure you have printed boarding passes. The app will regularly loose/forget your boarding pass or show you as not checked in and unable to check in even though you are holding a physical paper boarding pass.