To fix this, update ethtool in Ubuntu to the later versions.  I have run into this issue now in Cert when customers are testing higher end NIC devices.  The current version in Xenial is 4.5, and it looks like the current version in Artful is 4.8.

My customer tested this with 4.11 and you can see the differences below:
ethtool	1:4.5-1
Settings for enp94s0:
	Supported ports: [ FIBRE Backplane ]
	Supported link modes:   1000baseKX/Full 
	                        10000baseKR/Full 
	                        40000baseKR4/Full 
	                        40000baseCR4/Full 
	                        40000baseSR4/Full 
	                        40000baseLR4/Full 
	Supported pause frame use: Symmetric Receive-only
	Supports auto-negotiation: Yes
	Advertised link modes:  1000baseKX/Full 
	                        10000baseKR/Full 
	                        40000baseKR4/Full 
	                        40000baseCR4/Full 
	                        40000baseSR4/Full 
	                        40000baseLR4/Full 
	Advertised pause frame use: No
	Advertised auto-negotiation: Yes
	Link partner advertised link modes:  Not reported
	Link partner advertised pause frame use: No
	Link partner advertised auto-negotiation: Yes
	Speed: 100000Mb/s
	Duplex: Full
	Port: Direct Attach Copper
	PHYAD: 0
	Transceiver: internal
	Auto-negotiation: on
	Supports Wake-on: d
	Wake-on: d
	Current message level: 0x00000004 (4)
			       link
	Link detected: yes


And upstream 4.11:
Settings for enp94s0:
	Supported ports: [ FIBRE Backplane ]
	Supported link modes:   1000baseKX/Full 
	                        10000baseKR/Full 
	                        40000baseKR4/Full 
	                        40000baseCR4/Full 
	                        40000baseSR4/Full 
	                        40000baseLR4/Full 
	                        25000baseCR/Full 
	                        25000baseKR/Full 
	                        25000baseSR/Full 
	                        50000baseCR2/Full 
	                        50000baseKR2/Full 
	                        100000baseKR4/Full 
	                        100000baseSR4/Full 
	                        100000baseCR4/Full 
	                        100000baseLR4_ER4/Full 
	Supported pause frame use: Symmetric Receive-only
	Supports auto-negotiation: Yes
	Advertised link modes:  1000baseKX/Full 
	                        10000baseKR/Full 
	                        40000baseKR4/Full 
	                        40000baseCR4/Full 
	                        40000baseSR4/Full 
	                        40000baseLR4/Full 
	                        25000baseCR/Full 
	                        25000baseKR/Full 
	                        25000baseSR/Full 
	                        50000baseCR2/Full 
	                        50000baseKR2/Full 
	                        100000baseKR4/Full 
	                        100000baseSR4/Full 
	                        100000baseCR4/Full 
	                        100000baseLR4_ER4/Full 
	Advertised pause frame use: No
	Advertised auto-negotiation: Yes
	Speed: 100000Mb/s
	Duplex: Full
	Port: FIBRE
	PHYAD: 0
	Transceiver: internal
	Auto-negotiation: on
	Supports Wake-on: d
	Wake-on: d
	Current message level: 0x00000004 (4)
			       link
	Link detected: yes

Please update ethtool at least in artful to 4.11 so that at least this will land in 18.04 if no other major changes happen.

I would also like to see this updated in Xenial as well to address these issues in the current LTS.