Did you come through Knoxville this week? I heard someone saying they were traveling with their laptop & trying GMRS repeater. I was listening to the Knoxville "Lunch bunch net" & scanning the Oak Ridge 725 repeater.
I think the Chattanooga repeaters are all part of the NGA GMRS group. When they recently moved the one repeater from Lookout Mtn it has totally interfered with the Oak Ridge & it's linked repeaters. Ruined my ability to hit any repeaters now.
FM radio isn't connected to the "unlock" process. Notarubicon has the correct info on YouTube. It seems to only be for Amateur Radio units to open things such as GMRS, MURS & Marine bands. Think Baofeng 5r varieties. Unfortunately I've not found any such unlock for the UV-9G.
I live in the mountains of southeast TN. You should have been able to hear a lot of traffic from the NGa GMRS group as most of their repeaters are linked. I listen to their traffic on an HT.