D10D 5010 NOTICE: SESSION CONNECTING HAS TIMED OUT

I installed the D10D, now known as the 5010, models for about 60 users two years ago. These worked great with little to no maintenance. That was until CCM started getting more regular upgrades. Then some of my devices stopped checking in with the management profile.

Dell suggested that this was because my firmware was out of date. I was still using what came out of the box, 8.0_505. After getting some upgrades done, some users are getting an error on login; "NOTICE: Session Connecting Has Timed Out." If you click OK, your session is disconnected. If you don't want to keep trying, you have to move the window out of the way and continue working because the connection has been made successfully. 

Not all of the users get it, but the ones that do get it, continue have the problem. The problem is growing in number and Dell hasn't responded with any solutions in about 2 months. 

Does anyone has some suggestions, because I need the devices to check in with device manager so the firmware updates are necessary, but I also can't force my users to continuously try to login until they don't get an error?