Another RealTek 8125 Funny

[Rattlehead.ie]

Hey guys.
Have myself a new Asus PN50 and installing Proxmox on it. I have followed some of the tutorials, but as Im running the newer build of promox I thought most of these drivers were installed. During the installation the proxmox install detected the realtek NIC and infact as DHCP was available on the network at the time, picked up an IP address itself.(see attached) However, when everything reboots and I am presented with login screen (CLI) I login and have no network connectivity, and the NIC is in a down state. .

If I do a
"ip addr show" I see my RealTek 2.5G 8125 but it's in a down state despite it being connected to a working switch port.

Further if I do a "lspci | grep Ethernet" I get

02:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. Device 8125 (rev 05)

So it does look like it knows the device is there and what it is.
Running "ip link set enp2s0 up" it brings the I/F up but no packets at all.
Am I still missing the drivers here? What can I do to get this work? The other thing to note is after every reboot this I/F stays down. Any help would be appreciated.
From my /etc/network/interface config.

auto lo
iface lo inet loopback

iface enp2s0 inet manual      <this is the Realtek 2.5G 8125

auto vmbr0
iface vmbr0 inet static
      address 172.16.252.5/28
      gateway 172.16.252.1
      bridge-ports enp2s0
      bridge-stp off
      bridge-fd 0

What Im hoping to achieve it an ability to run 3 or 4 machines some will not be in the same VLAN as the 172.16.252 network that I use for management.

Just an update further. I followed This Tutorial post installation of proxmox not during the install. It all seems fine till I try to install the matching pve-headers and it says it cant find it for 5.13.19-2
Couple of notes.
During install it says r8169, after install it says 8125?
Should I not see my vmbr0 interface when I do a "ip addr show"

 

[Rattlehead.ie]

Ok least I know Im on the right track, but what dependency.
What I have been able to do is run
1. systemctl stop networking
2. systemctl start networking.

The vmbr0 and physical interface come up and work perfect, full connectivity.
However, if I reboot then the issue comes back and as the system is not expected to be sitting on my desk and in a rack, this wont do.

I have read about running
systemctl mask ifupdown-pre.service

However this doesn't fix the issue when the system is rebooted.
Is there a way to identify what the dependency is and stop it from being checked so I can reboot this system without a monitor and keyobard attached.

 

[Rattlehead.ie]

Further update:
Following the cron-job details in this thread. I created a cron to restart the services on reboot.
A bit of a messy work around, but it did what I needed too.
If anyone in the know wants to reply, i would be grateful in finding out how I discover what "dependency" was stopping the network services from starting.