Flight change - is this correct?
we booked a return domestic flight a few months ago. on checkout we purchased an upgrade for the return flight to first class.
this week we need to arrive at our detonation a little earlier, so we made a flight change to the outbound leg. no fee and seats and fare class all the same, just a slightly earlier departure.
when trying to confirm the change, delta also modified the return leg. same return flight but removed our first class upgrade.
is that an expected behavior for a flight change, and if so does it make sense in future to book 2 one way flights if we think there’s a risk of changing flights?