Changing seats online not available on QF anymore?

Hi gurus, has anyone else lost the ability to change seats for bookings with QF? I have 7 flights booked between May and December, a mix of domestic and international, all in J. Some solo, some with my wife. Some with me as the travel arranger, some not. Some with upgrades to F requested, some not. All are booked on the QF website (not through a third party). Regardless of whether I use the app or the website, neither of us can change our seats for any flight - we just get the option to select a preference (aisle window / forward / rear etc) and a message saying "individual seat selection is not available for this flight". We've both been WP for years and never, ever had an issue. (And yes, I know I can phone them, but I'm just curious to know if anyone else has / is experiencing the same). TIA.