DisplayName always "anon" or "undefined"


When i start a session the displayName of my users are always “anon” or “undefined”. Or my firebase user displayName is correct.

I tried updateCurrentUser but when i create a new channel, the correct username appear only in properties, not directly in members :

 [{"callStatus": "AVAILABLE", 
"displayName": "undefined", 
"displayPictureUrl": "https://api.chatkitty.com/v1/picture/undefined", 
"id": 336489, 
"isGuest": true, 
"name": "undefined", 
"presence": {"online": true, "status": "AVAILABLE"}, 
"properties": {"displayName": "Apple5", 
"expo-push-token": "ExponentPushToken[h6TTB1PyUSt_eHSz5KW3r5]"}, 
"type": "PERSON"}, 
{"displayName": "anon", 
"displayPictureUrl": "https://api.chatkitty.com/v1/picture/anon", 
"id": 336993, 
"name": "9bTR7Acme1MgwgrBOm8dy6P00Pf1", 
"presence": {"online": false, "status": "UNAVAILABLE"}, 
"properties": {"displayName": "Zooooo"}, 
"type": "PERSON"}]

Thanks for your help