Help getting SFP+ / 10GTek adapter working with OPNSense on fitlet2

[zxurian]

I have a fitlet2 PC (https://fit-iot.com/web/products/fitlet2/) that has been running OPNSense like a champ for a few years now. No issues at all.

Upgraded my home internet to 1.2G w/ Comcast and want to take advantage of higher throughput. Bought the SFP+ add-in board for the fitlet, installed it, OPN _appears_ to see the interface. It's listed in the settings as an available interface. I plugged the 10GTek (https://www.amazon.com/10Gtek-SFP-10G-T-S-Compatible-10GBase-T-Transceiver/dp/B01KFBFL16/) SFP+ adapter in, and plugged rj45 cable into network, however OPNSense isn't getting an IP address on that interface.

My knowledge of networking doesn't extend to being able to diagnose whether it's a problem with OPNSense & the SFP+ interface, or between the interface and the 10Gtek card (or both).

Would appreciate any assistance with trying to figure out what/where the issue is so I can try and use the SFP+ interface for additional bandwidth

Screenshot of existing regular 1000baseT interface on LAN network https://i.imgur.com/TwdeJ7n.png
Screenshot of SFP+ interface in OPNSense https://i.imgur.com/VDUSR8T.png