PPPoE connection error = Timeout waiting for PADO packet

Hi all

Current setup:Vodafone VDSLSophos UTM 9.5 running on an Intel NUCnic0 -> lanusb\eth nic1 -> DrayTek Vigor130 (PPPoE pasthru)UTM handles creds and vlan tag of 10Modem has no real configuration apart from passthru tickedRunning sweet as no problems.

So I build an ESXi 6.5 with 2x nics (HP desktop)built-in nic0 -> lanTPlink 3648 nic1 -> DraytekVMXNET3 drivers

I built a Sophos VM with same config, modem config untouched but the UTM wan nic1 never comes up.UTM PPPoE error log bleats on about timeout waiting for PADO packetModem reports no response from server-end (or something to that effect)

Thought it might be esxi dicking over the vlan tag, so set vlan10 on the vmkernel, no change

Changed esx driver to that off e1000, no change

Swapped nics over, so onboard went to modem and tplink went to lan, no change

Dicked around with various modem settings, no change

Smacked head on wall, no change

Any idea's on what could be going wrong?