AC2 HND-YYZ, 29/40 in J. Was told JPY 210000 (~1800 CAD) from Y standard, offer was accepted for 2 pax at T-12.

Weird (interesting?) dp... SGN-HND-YYZ, ANA > AC, protected connection can't apply LMU online/on phone (was told to go to check in counter). However, SGN-HND-YYZ, JAL > AC protected connection was able to apply LMU online (via app).

I know this probably has something to do with ANA being *A, but what's the technical reason LMU can't be applied for those connecting from ANA? Is it because if connecting from non *A, you aren't technically "checked in" for the connecting flight?

EDIT: turns out that the ANA > AC pax eventually received the LMU offer in the app as well.