RHEL 5.11 Machines periodically falling off Windows Domain

We are having some issues with our Redhat 5.11 machines that are continually falling off our Windows AD domain. The frequency of the issue is sporadic..we have seen between a couple of days to a couple of weeks. When doing a wbinfo -m we see that the machine still shows its a member of the domain, but doing an id '$user' fails and we have to readd the machine back to the domain. Just fyi, We do have mixed environment of windows machines as well and they don't experience the issue.

Trying to find a start point on where to troubleshoot this issue. Any help is greatly appreciated!