Originally Posted by bennos

Your Y segment is likely booked in (N) class. As such it falls at the end of the DM class hierarchy for upgrades (YBMHQKLUTEN). So you will be behind all other DMs on paid tickets and behind any DMs who obtained their award ticket before you. (Effectively, you agreed to be booked in a Y seat when you booked your ticket.)

If (R) opens up, you could rebook if your other segments are still available.