i think i might have figured it out.
adrien likes ladybug, obviously.
but he also kinda likes marinette, as seen with how happy he got when he figured out she was ladybug is chat blanc.
he also likes kagami, even if it was more of having found kinship in someone with a similar familial life.
ladybug doesn't like him [chat] back. so he doesn't GIVE UP on her but he doesn't pursue her as much.
he thinks marinette doesn't like him bc of how she acts around him.
but he does know that kagami likes him back, and he liked her enough as well to want to pursue a relationship with her.