The code I wrote with rxDart is not readable - flutter

Question

I'm listening to 2 collections on firebase using RxDart. The data is being pulled, but the merge with RxDart does not go into my code. So that part passes. What could be the problem??
User and Conversation collections are listening. I can reach this data and ı can write on the console. But Rx Code passes.
#override
Stream<List<Chat?>> getAllConversation(String userId) async* {
Stream<List<Conversation?>> conversationStream = _firestore
.collection(_conversationCollectionName)
.where(
Conversation.memebersKey,
arrayContains: userId,
)
.orderBy(
Conversation.sentAtKey,
)
.snapshots()
.map(
(event) => event.docs
.map((e) => _getConversationFromDocumentSnapshot(e, e.id))
.toList(),
);
Stream<List<User?>> userStream =
_firestore.collection(_usersCollectionName).snapshots().map(
(event) => event.docs
.map((e) => _getUserFromDocumentSnapshot(
e,
))
.toList(),
);
yield* Rx.combineLatest2(
conversationStream,
userStream,
(List<Conversation?> conversations, List<User?> users) {
print('Rx içinde giriyor');
return conversations.map((conversation) {
if (conversation != null) {
var otherUser = conversation.memebers[0] == userId
? conversation.memebers[1]
: conversation.memebers[0];
bool isOwnMessage =
conversation.lastUserId == userId ? true : false;
User? user = users.firstWhere((user) {
return user!.userId == otherUser;
});
return Chat(
id: conversation.conversationId,
user: user,
message: conversation.lastMessages,
unReadMessageCount: isOwnMessage ? 0 : conversation.unRead,
isOwnMessage: isOwnMessage,
sentAt: conversation.sentAt,
senderId: userId,
);
}
}).toList();
},
);
}