Looking at travelling MAN-SIN-PER towards the end of the year, but it seems like almost all days in December are already fully booked for economy on the MAN-SIN leg, with the Singapore site instead offering MAN-FRA-SIN-PER as the closest alternative.

I know Singapore sometimes open up blocks of seating closer to the dates, but as I'm looking to book early, this is more than likely going to force me to another airline.

Is this the effect of the new IAH-MAN-SIN route? Or are Singapore just holding back more seats than usual? Anybody have any idea if more seats will free up in time?

Thanks !