Have been getting an "Unable to Authenticate" error for some time upon "Login using Plex." Logging in as a local user instantiates infinite loading. Updating and redeploying doesn't seem to address the issue. Error from the logs "Plex Server didnt respond with a valid 2xx status code, response code: 404"
This has been happening for months, so I cannot provide an exact date at which it began to occur.