Join Date: May 2004
Location: SIN (LEJ once a year)
Programs: SQ, LH, BA, IHG Diamond AMB, HH Gold, SLH Indulged, Accor Gold, Hyatt Discoverist
Posts: 7,726
In your case this seems to be a *A award and that's the issue. Apparently, SQ can't modify such awards and just revalidate, it requires a cancellation and rebooking even for only a date, time, flight change while maintaining the exact routing.