Hi there @senh ,
Try to delete yourself/name everything again over EmoPet App, then once again introduce yourself, ask him what is your name wait for his reply if everything correct…give him your Birthday…As soon as he say he will remember it, make a test by saying ‘’ EMO…It’s my birthday! and see what happen or if he sings a birthday song for you.
You can also click the link below where @MasterAbbott’s experience explanations about Birthday Feature.
GOODLUCK AND BEST REGARDS!