I’m booked on the island hopper from Guam to Majuro. Each leg is separated in order to improve my chances of getting upgraded. I have a full fare Y ticket so I’m getting instant upgrades into PN. Currently I have gotten upgraded on each segment except for the KWA to MAJ leg. When I search for the the leg there are no business class seats available in any fare class. Additionally, for the return, I have gotten upgraded for all segments except for the last (TKK to GUM) and there are no business seats available in any fare class.
So I look at the seat map and see one open seat in business on the TKK to GUM leg (no open J seats on the KWA to MAJ). When I click it, it takes me to a page where is shows me upgrade options for all the legs on my itinerary. It tells me that I can use a GPU/RPU or miles to upgrade the TKK to GUM and I can only use a GPU to upgrade the KWA to MAJ. There is absolutely no indication that this is a waitlist.
I find it interesting that one offers RPU/MileagePlus upgrade and the other does not, while the United's search function shows zero availability in any fare class for either of these flights. Any idea what’s going on?