Not sure how it happened, but I booked a flight on LX in C, ZRH-NRT and only my middle initial showed up on the booking instead of my full middle name (i.e. Joe C. Smith instead of Joe Clark Smith).

This is a UA MileagePlus award reservation. Flight isn't until November, so plenty of time to fix. But is this a problem I need to call in to change with UA or do I make the change with LX so my name matches my passport?