Hey there, did the troubleshooting steps help?
I surely don't see how the troubleshooting you provided would work. There is no link in that information regarding trusted places, smart unlock, or even security.
The smart lock on my S9+ was not workng correctly either. I entered the actual address and the circle around it on the map was correct, but the feature would not work. I edited the address using latitiude/longitude coordinates and had the same problem. Finally, I eliminated both addresses shown and used only a GPS signal (by tapping on the map shown for my current location). Once entered, i restarted the phone and the smart lock finally worked.
I just almost lost it trying to fix this.
Finally I deleted the GPS. I couldn't remove the Google Home address But I turned that off too restarted Turned the Google Home address (should work with GPS location too) then I powered off.. Don't just restart because that does nothing.
I rarely power off my phone but I guess I should start.
Give this a shot; https://www.samsung.com/us/support/answer/ANS00077687/