UEFI Network Boot options missing on 7450 with BIOS A13

After upgrading a lattitude 7450 laptop to the latest BIOS, A13, both the IPv4 and IPv6 boot loader are missing when wanting to perfrom a UEFI network boot, Encountered this on all 7450 with BIOS A13. The enable UEFI network stack check box is checked as it was. Any idea where these options went? It is not possible to perfrom UEFI network boot anymore we wanting to reimage it.

The only solution we found around it is to downgrade the BIOS to A12, and then they are back. 

Is this a miss from Dell? Cant image they did this on purpose. 

Thanks.