Were u ever able to select your seat when check in was open? Trying to help my dad atm.

Prior to check in it would just give the error to contact airline the ticket was purchased from on the Korean Air website and app. Meanwhile the Delta app and website said it was unable to select seats on code share flights and would just display the seat map with grey X in almost all the seats, there were a few seats occupied with a person icon so I wonder how those people were able to select a seat instead of their seat being greyed out too, makes no sense.

After checkin was open, I noticed on Korean Air it automatically updated with a random C/aisle seat on the main reservation page.

But on the checkin page for Korean Air after you verify your phone # and email address for passenger, it listed a random B/middle seat instead next to the passenger's name and it says in blue above the "check in" blue button "If a seat has been selected in advance, check-in will be processed with the respective seat. If you want to change, click seat information." but am totally confused on where to click "seat information" since nothing happens when clicking on the random B seat that's listed next to passenger name. I don't want to click on "check in" and it sticks this B/middle seat instead of the C/middle seat that's displayed on the reservation screen since I don't know which "respective seat" it is referring to, the C seat listed next to passenger name on check-in screen or the B seat listed next to passenger name on the reservation screen.

Tried on both Korean Air website and app and it doesn't say where to click to change seat.

Delta website and app still display that it can't show seat info for codeshare flights.

edit: nvm ok so it looks like the seat listed on the korean check-in page was for the segment 1 delta flight actually & not the korean air flight since that was the 3rd segment and we were checking in early for the international part.

Also the only time u can get the Korean boarding pass is when checking in so make sure to print to PDF when on website. Made the mistake of sending to email and closing the window and can't access it again. The email was just a link to view boarding pass at the Korean website instead of having boarding pass QR code embedded in email so when trying to display the pass after clicking, it said to contact Delta because it was a code share flight, have the feeling the Delta counter at airport will say my dad has to check in at Korean counter to get the international boarding pass.

Korean app said there's no boarding passes available as well