Hello all - first time poster (long time reader).

I am a SE and flying YYZ to YVR in the next few days on a latitude flight pass. I have a confirmed upgrade to J (via upgrade) on the return and have not requested an upgrade on the outbound as my schedule was still in flux. As such, I am trying to change my outbound to a later flight (same day) and the AC call Center says they can’t do it without recalling the eupgrade on the return (thus taking away a confirmed upgrade). There is no R space left so hesitant to give this up.

This doesn’t make sense as to why my return flight / upgrade would be affected and I am fairly confident I have changed one leg before in isolation. Any guidance from the forum?