Had a weird issue today with availability. Both ANA tool and BMI CSA could see award availability on an SQ flight but when he tried to book it, it comes back as "waitlisted." Huh? I've seen issues like this with SQ flights on revenue bookings but I've not experienced it on award bookings. Spoke to a supervisor who mentioned that it was an ongoing computer issue with SQ and TG flights, they'd show seats as available but in reality they might not be there. Or could this be a new method of 'filtering?' In the end I booked the next available flight, lengthening the transit in SIN by a few hours - not ideal but hey.