All my playable characters share the same birthday, as I depict them as alter-egos. When it’s the day, Nana(best friend of all three of my villagers) comes over to my house of whichever character I play as. Same thing happen when I log into my other villager. It’s like as if Nana would erase the birthday celbrant name on the Happy birthday banner everytime lmao. No mention of my other characters’ birthdays at the same time in one log in other than the bulletin board.
Now because of this, and I would never have Stella in my town, I never experience birthday shares with animal villagers. Link to post?