High time to have internet avalaible

Do you have STAS Quarantine enabled? 

And how many AD Servers do you have? Could one AD server "invalid"? But this would not indicate such a high latency. 

How fast do you see a authentication request in logviewer after somebody logs in? 

Hello Lucar,  

Thanks for helping me...   

1) Yes STAS Quarantine are enabled    

2) I Have 2 DC of 4 enabled with STAS, DC works well and Stas LOG not reporting big issues...

3) Authentication request is executed pretty fast.

Following your hint, could be usefull to disable "Restrict client traffic during identity probe", what does that imply?

Thanks,
Alessandrp

You should disable the quarantine and try again. It could cause this long time until it works. 

Ok, Just disabled, let's see how it goes..

You need STAS at every DC (if i understand this correct).
XG don#t ask a DC but the DC (STAS at this DC) forward the logon event to the XG(s). So all logon-enabled DC's should be able to send logon-events.
Without authentication, your internet-access is more fast?
(you may create one rule for one PC to test this)

After prolonged tests with my users, this solved my problem, Thanks!