Troubleshooting Plesk Login to Panel Issues
After applying the 8.2.0 update, certain environments may experience impeded function of the Login to Panel button on Plesk services.
Please apply the 8.2.1 Maintenance Release via the Utilities > Update WHMCS page.
Enable Allow IP address changes during a single session under Plesk > Tools & Settings > Active Plesk Sessions > Session Settings on the Plesk server.
A hotfix has been created for 8.2.0 only to correct this behaviour: