After quite some searching and using this query ("how to expose kvm vt in microsoft hyper-v"), found the following answer which resolved the issue on my Windows 11 machine on which I had Hyper-V enabled and wanted to create a Proxmox VM to play with.
Correct resolution:
To expose KVM VT (virtualization technology) in Microsoft Hyper-V, you need to enable "nested virtualization" on the virtual machine by using the PowerShell command "Set-VMProcessor -VMName <VMName>...
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Correct resolution:
To expose KVM VT (virtualization technology) in Microsoft Hyper-V, you need to enable "nested virtualization" on the virtual machine by using the PowerShell command "Set-VMProcessor -VMName <VMName>...
Read more