Winbindd loses authentication

[Guest]

[Belini]

Environment: Endian + Proxy + ad Win2k8
Non-transparent proxy
Number of Customers: 800

Proxy works normal authenticating with ad, after a few days the proxy can no longer authenticate users in ad, but still communicating with it.
The result of #wbinfo -t = success

After restarting the services:
c-icap
winbindd

It works again, does anyone have a definitive solution?