Winlogon <GPClient> took 121 sec to handle event (Logon) - DNS Issue?

Well, the subject of your post asks a completely different question than the contents of your post.

So first, the subject. No the GPClient event log is *not* a DNS issue. That's a group policy issue. And not necessarily an error.

Now for your question. "The primary DNS is supposed to be 10.219.1.2"

In the screenshot you posted, that *is* the primary DNS. So if that's what it is supposed to be as you claimed, there is no issue there either.

It sounds like you have a rogue DHCP Server on the line. Temporarily stop the DHCP Server on the server and from a workstation do a ipconfig /release followed by a ipconfig /renew. If it renews you have another DHCP Server somewhere. Look at the gateway address and visit it with IE to try and figure out what and where it is,

Sorry I wasn't clear. The logon time became very long after the default gateway switch and after googling the topic DNS came up. After noticing 2001:558:feed::1 in the primary DNS field I focused my question more on that. I'm going to check the settings on the comcast gateway when I find the password and try lockdowns suggestion to check to make sure DHCP isn't running elsewhere on the network.