I have since found that each time I attempt to use the links for single sign on the following entry is placed in the activity log:
"Single Sign-On Request Failed with a Fatal Error:"
It does still redirect to cPanel and appears to sign in with the correct user, but it does only do so using the IP address.
Since the update any of the cPanel login links are using the IP address only, which combined with SSL is causing certificate errors to show up, doesn't look very good. On the last 5 version it used the server hostname without any problem. I've been unable to find any template direction on where this is defined to see if I could remedy it.
Is anyone else having this problem?