I have a Y segment from MUC to KRK on LH as a UA codeshare. Two days ago, I went online and paid $14/ seat for exit rows. I am *G, and this was a 'classic' ticket, not 'light'.

I have a native LX segment also and called them to get a seat a week ago and it was the same $14. They also sold me the seats on LH but this dropped off the reservation a couple days later. I was not able to buy seats on the LX site for the LH segment. You would think that they use the same software and back office.

Buying what seems to be the same flight and ticket type on LH for that segment allows for some free seat assignments including exit rows. Odd that you buy it from them, it is free. Buy it from United, and it is not.