samba - Jul 2015 - mount.cifs drops connection to windows server on group policy refresh

Client is mount.cifs version: 6.2 on Red Hat Enterprise Linux Server release 7.1
(Maipo)

Connecting to a Windows 2008 R2 File Server.

The client will maintain a connection to the server until a group policy refresh
is triggered on the server.  Anytime a group policy refresh occurs on the
server, the client is disconnected.

If we don't explicitly specify vers= option it will reconnect after ~15
minutes.

If we set vers=2.1 it will "Input/output error" if attempting to ls
the mount point; it will not reconnect without explicitly umount first and mount
-a