@gaptoothgonni Well darn, have you tried booting with snponly.efi instead of ipxe.efi? It wouldn’t make a ton of sense if that worked but something else to try.
If it’s booting to the wim though, it should just be getting the drivers from the wim unless ipxe somehow changes how they’re presented, which I don’t think it does but that’s also the only difference between where it’s working. Might be worth looking at https://github.com/ipxe/ipxe/discussions and seeing if anyone has had similar issues. Since you’re just using FOG to create the ipxe boot menu, it’s not likely anything within FOG that’s causing this. You could try ipxe’s pre-built boot files, though they won’t have the embedded fog stuff https://boot.ipxe.org/ but maybe will make a difference. There’s other ipxe efi files you can try too, or try an older one ( I think we still include some legacy ones in /tftpboot)