[atlas] Shiny new v5 probe reveals problem with virtual probe

Hello, everyone. TL; DR: clue needed configuring Turris Omnia for virtual Atlas probe. I'm delighted to have a shiny new v5 probe, which is operation since the day before yesterday. The new probe has been automatically tagged "IPv6 Works". On account of this, I've noticed that my virtual probe, running on my Turris Omnia, has the complementary tag, "IPv6 Doesn't Work." I suspect that I've not configured firewalling on my Turris properly. If any of you have sorted this, I would appreciate some clue. Thanks in anticipation. Niall