NIC shuts off during Windows boot

[NiKiZe]

I'm guessing you are using PCBIOS mode, but could you confirm that it isn't in EFI mode ?

During the boot process windows loads it's own drivers for the NIC and iPXE goes out the window, so at every boot you will actually see the nic being reset.
If this is what happens, or if it is something else is unclear.

It is also quite common that Windows 10 has issues with iSCSI. If possible please confirm that the same version/build works with an intel based nic.