We have a customer reporting after long inactivity (such as over night), the first user that tries to log into forms has an issue with the first attempt. They are directed to the LFDSSTS login page and after clicking the Windows Authentication button, they just get a spinning loading icon indefinitely. When they reload and click the Windows Authentication button, they are logged in without issue.
They have the LicenseManagerSTSAppPool Start Mode set to AlwaysRunning. What else can we check to try to resolve this annoyance?