A basic guide

[NiKiZe]

You need to be more specific about what works and what doesn't

My guess is that your DHCP does not give the correct info for network boot.
Hyper-V is horrible client to debug this, and windows DHCP service is horrible to configure.
If this is the state you are in then I would start doing packet capture with for example wireshark to figure out which information is in the DHCP traffic, and to see if there is any TFTP traffic.

Reading over your notes again I'm currious where you have added ipxe.efi or snponly.efi?
Please see https://2pintsoftware.com/whitepaper-usi...e-booting/ for some good pointers.