Setting up fiber PPPoE connection

[markfree]

Finally, it works.
The issue turned out to be the module firmware, as you suspected.
Initially, I had concerns that a failed firmware update might render the module inaccessible, especially considering I cannot access its serial console.
Although I had noticed the new firmware versions, I didn't deem it necessary to upgrade immediately. I wanted to ensure that everything was functioning before attempting any updates.
Moreover, given my limited familiarity with optical networks, comprehending the various modes and options presented a bit of a challenge.

The module was initially running version "v1.0_220923". When all else failed, I took the step to update the firmware to the most recent version, "V1.2.2-221209". After configuring the module, voila! OPNsense successfully acquired new public IP addresses. No VLAN configuration was needed by-the-way.

What a journey!
I am immensely grateful for all the insights and tips provided to me. These inputs were incredibly valuable and guided me towards the correct adjustments. The learning I've gained throughout this process has been invaluable.
Thank you.

Now, a new journey begins... optimizing everything. 

[meyergru]

You're welcome and congrats! That was quite a steep learning curve and you did very well.

I personally find it easy to isolate technical problems when I can check each link in the chain in turn, like OSI layers in this case. Many people do not understand that and give up without even knowing what exactly went wrong.

Admittedly, with GPON technology, there are many things you have to know (or learn) in order to get things working and it takes determination to follow through - which you had.