This problem with Hulu is constantly recurring based on reports in this forum, and it results in missed recordings. About every 3 or 4 days I have to remote in to my Channels DVR server Win 10 machine, launch a Chrome incognito window, manually login to my Hulu account (I usually go into my account settings screen then) and minimize that window. For the past month this seems to reduce the amount of missed recordings due to authentication problems, and I get the authorization email much less frequently. My Hulu account is only accessed from this one computer, at one static IP address.
I wish there was a way to resolve this without recurring user intervention.