@Huecuva Well poo
I think a solution exists we just gotta find it.
So just want to do a quick review of where we’re at.
The problem is that after imaging it does boot into windows from the fog pxe menu and then it never works again?
Or is the problem that you image and then it doesn’t boot to windows at all? Sounds like you said it seems to work once, then the windows setup changes the boot order (which is something it does with bcdedit and you can actually do this manually as well (try bcdedit /enum all to see all the boot options windows can set from command line. You can make it put the network boot first, it’s just a bit of a complicated task)
Anyway, since refind did work from usb that means it should work. I have seen it not work from pxe when it didn’t work from usb.
Some things worth trying are as @george1421 mentioned different ipxe.efi files. If the one that is working at the other site didn’t do the trick one of the other included ones (realtek.efi, intel.efi, etc) might make a difference.
Another thing would be to take the refind.conf from the working usb and put that on the fog server. I’d adjust it to not use the gui (can’t remember the exact setting in the file, but I remember it being pretty clear) and see if it works via pxe.
You could also consider using a bootloader such as grub2win and putting a local copy of the ipxe.efi file on each computer’s efi partition. Then when you need it to boot to fog you have a script that changes the grub.conf boot order. But that’s a super complicated approach. I actually do this because I used to have random issues with the windows bootloader and I also like having the menu at each startup to go to fog, uefi firmware settings, or windows. I can walk you through this but I make it part of my image, so you have to get it to boot to network pxe at least once.