Looking at the information you provide you might have a bad NAT setup because if done right you should be able to SSH. Just create a new NAT on the HyperV, set VM to use new NAT, and see if you get the same issue.
On host using PowerShell run;
$switchName = "InternalNAT"
New-VMSwitch -Name $switchName -SwitchType Internal
New-NetNat –Name $switchName –InternalIPInterfaceAddressPrefix "192.168.0.0/24"
$ifIndex = (Get-NetAdapter | ? {$_.name -like "*$switchName)"}).ifIndex
New-NetIPAddress -IPAddress 192.168.0.1 -InterfaceIndex $ifIndex -PrefixLength 24
If you do no have DHCP on the host you will need to set IP manually on guest VM to an IP in the NAT range.
Then you should be able to SSH into VM from Host on port 22
Reference:
https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/user-guide/nested-virtualization