You didnt provide enough information to even start debugging. You have to switch dtb link in boot and reboot for Omnia to use SFP instead of copper WAN. So do:
ln -sf /boot/armada-385-turris-omnia-sfp.dtb /boot/dtb
And reboot and post the output of:
dmesg | grep -E "(sfp|eth2)"
I am using SFP with same single SC/APC connector and works fine here. Its up to SFP what laser supports and connector not the router its plugged into.
In other hijacked topic you stated this. Is it solved then?