Issue using few e1000 nic in xen

[Mega MoiX]

Hello everyone,

I hope everything is going fine!

Thanks for your hard work;-)

I am trying to migrate my personal environment bare metal from Ubuntu 16.04.x 
with xen like 4.4 or 4.6 ? to Ubuntu 20.04.x with xen 4.11 for nearly one year 
now without success.
I use those two USB drive to boot so I can do trials with the new env, then 
rollback to use the machine as before when I meet issues.

And I have this old virtual machine that I can't modify, which is working fine 
with the old env with multiple e1000 nic.
But on the new vanilla environement same xl config file with mutliple e1000 nic 
it doesn't boot cause it cannot allocate memory as it sems to me cause of the 
multiple e1000 roms?

Error is:
qemu-system-i386: -device e1000,id=nic1,netdev=net1: xen: failed to populate 
ram at 3100c0000

Any advices to where I could start to understand this  ?

Thanks in advance,
Have a nice day,
Best Regards,
Mickaël.

PS:

#!/usr/sbin/xl

name = 'test1'
builder = 'hvm'
vcpus = '12'
memory = '11264'

vif = [
'mac=XX:XX:XX:XX:XX:XX,bridge=Xbridge,model=e1000'
,'mac=YY:YY:YY:YY:YY:YY,bridge=Ybridge,model=e1000'
,'mac=ZZ:ZZ:ZZ:ZZ:ZZ:ZZ,bridge=Zbridge,model=e1000'
]