Notification problem – Hangouts Review

When someone send me text on hangouts i am not get notifications right time, when i go inside then i see u may understand, its a long time same problem when i use pc have same problem in android same problem, now i am use iPhone 6, updated everything is good working mobile but have only one problem in hangouts other inbox perfect working please fix this problem thank you.
Review by dimag khrb kiya hwa hy on Hangouts.