Came across this thread through Google, because I have exactly the same problem with an XG-C100C 10G card in a Debian 10 machine. So this doesn't seem directly related to Unraid.
# ethtool -i ens5
driver: atlantic
version: 2.0.3.0-kern
firmware-version: 1.5.44
expansion-rom-version:
bus-info: 0000:0d:00.0
supports-statistics: yes
supports-test: no
supports-eeprom-access: no
supports-register-dump: yes
supports-priv-flags: no
# uname -a
Linux afnet 4.19.0-8-amd64 #1 SMP Debian 4.19.98-1+deb10u1 (2020-04-27) x86_64 GNU/Linux
If someone found the source problem and a solution, it would be great...