If you're talking about the Singapore side of things, is it possible that it's not intentional? The working hours for that team are likely going to be whatever

If you're talking about the Singapore side of things, is it possible that it's not intentional? The working hours for that team are likely going to be whatever convenient for the Singapore team, so they might only have Singapore locals applying. There could be other factors like maybe the pay rate isn't good enough for expats in Singapore to apply (assuming they make more than the locals).