Fetching messege from layerkit ios error

Question

I am creating a group through layer kit iOS SDK. Owner of group is sending push to participants and one message while creating a group. Problem is that when participants fetch the message the conversation object comes null some times, below is my code

query = [LYRQuery queryWithQueryableClass:[LYRConversation class]];
 query.predicate = [LYRPredicate predicateWithProperty:@"identifier" predicateOperator:LYRPredicateOperatorIsEqualTo value:eventDetail[@"layerConversation"]];
NSError *error = nil;
conversation = [[self.layerClient executeQuery:query error:&error] firstObject];

NSLog(@"%@?????????????????? and layer client  %@",conversation, self.layerClient );