Hello,
Kindly proceed with the steps below:
1. Reproduce the issue.
2. Collect a technical report. To generate the report, right-click on the Parallels icon in Dock > Help > Send technical data > check "Attach screenshots..." > press Send Report, and provide us with the report's 9-digit ID.
Regards,
If machines are taking a long time to shut down, it is usually due to background processes, system updates, or software hanging. Checking startup/shutdown.