One question and one heads up:

Heads up: A UA award ticket that includes (at least) 4Y (Discover Airlines) segments cannot be changed online once booked. I had an LH-EW outbound, 4Y-LH excursionist perk, UA inbound ticket. Once booked the online and mobile app change features were unavailable. This was true after flying the outbound. Only once the 4Y segment was used did the ticket become changeable again online.

Question: now that my ticket is changeable, I'm looking to change the return from departing LON to departing FCO (both back to USA). When searching as a new award ticket it's 31K return (I know! In the middle of high season summer travel). However, when I go to change my ticket it wants to charge me the full 40K miles. Why is this and would calling get me a refund of 9K miles as expected? (Original LON-USA return was 40K as well).

Thanks,
-RM