iPXE try to free memory without signature error

I have HP proliant DL360 client to be rebuilt with broadcom Nextream II
BCM5709 bnx2 NICs in them.

Boot Mode is set to Bios.
I am using Foreman 1.7

Clients are in a different subnet and I am using boot-iso for initial
After a short while, client hangs with "try to free memory without
signature" error.
From search, I see this is somewhat common with broadcom chips trying to
chain load isolinux–> ipxe.
Is there a fix for this problem to let me proceed with normal foreman build?
I think my other options are going to mean forgoing foreman's un-attended

For example, to test, I created a DHCP server over at the same subnet as in
the client, then pointed that client to use Foreman as the tftp server.
This does not work as there is no entry for the client in
/var/lib/tftpboot/pxelinux.cfg directory.
I thought about manually creating a file in pxelinux.cfg directory but I
think it will not work as ks file is built dynamically for each individual
I am not even sure if there was a way to pass proper ks directives to
client, the issue with NIC will go away with this method.

There is a last resort option of falling back to using older style
kickstart file, baked in to a OS dvd.iso file to build the system, but I
want to avoid that as much as I can.

Any input, suggestions, help appreciated.