Parallels with Windows 10 VM automatically shuts down after 30-40 min
The issue is that the VM itself is timing out. You have an Evaluation Edition only,  the Parallels page says "using an evaluation virtual machine".

The VM is actually from Microsoft.

I cannot find the exact details but from my memory Microsoft evaluation VMs time out after 30 minutes but other google results suggest that could be after the 90 days you are allowed.