Cisco AnyConnect Timeout Error

Hi everyone,

In our environment we use Duo for 2FA that syncs with AD, and Cisco AnyConnect. I have one single user who all of sudden started getting timeout errors in AnyConnect AFTER he is authenticating successfully by pressing "approve" on the Duo push notification. So far the only thing I have been able to find in any logs was in Splunk, and this is what I got-

"AAA user authorization rejected" user with the issue's account

"reason: AAA server has been removed"

Everything on his Duo account looks fine, I've tried reinstalling AC several times, resetting his password in AD to force re-authentication, and I even tried having him use a different laptop and the problem followed him to that other laptop. Not sure why this just happened at random, but he was previously logging in regularly without any issues. If anyone has seen this problem before I'd love to know how you solved it! ;) Thanks for your time!