typeorm leftJoinAndSelect get one item of relation array

I am Korean student. please understand my bad english.

I am trying to get chatting_room with participants
and the chatting_room have participant who is loggedInUser.

here is my code

await this.Repository
    .createQueryBuilder("room")
    .leftJoinAndSelect("room.owner", "owner")
    .leftJoinAndSelect("room.matching", "matching")
    .leftJoinAndSelect("room.participants", "participants")
    .where("participants.userId = :userId", { userId: loggedInUser.userId })
    .getMany()

there are two participants in chatting_room ( ManyToMany)
but result show me only one that is loggedInUser
I want to get all participants .
what is the problem ?
please help me !