Hello, @yu-chieh.tsai . . . I have moved your new topic to this ongoing discussion for issues like yours.
Please read through some of the posts here including mine above yours. Sometimes the way you pronounce your commands or how far away when you are speaking to him may make it hard for him to understand you.
You may wish to submit your voice here to help EMO understand you better.
If nothing else works, there are instructions for contacting Support at service@living.ai in this thread also.
Let us know how it goes.