Issue with SFP-GE-BX Connection on OPNsense Firewall

[mxm_marcin]

In the firewall, I have installed a singlemode SFP-GE-BX transceiver, which appears on the list of compatible transceivers with OPNsense. My problem is that after connecting the fiber optic cable to the transceiver, the firewall shows "no carrier" and there is no uplink on the interface. I am certain that the cable is fine because the connection works perfectly on the Fritzbox router.

The installed transceiver is visible from the CLI, and the RX Power value changes depending on whether the cable is connected or not.

The installed transceiver supports 1 Gbps, while the motherboard supports 10 Gbps. Could this be a problem?

I do not find any hints in the logs that could be useful for further debugging.

Do you have any suggestions on where else I could look?