I'm having the same problem,for months now, with my Note8 Edge trying to smart view with my Samsung 55" curved smart tv.
I've read n tried all the suggestions in this topic feed with NO solution.
Funny thing though, smart view works fine with my old Note4 edge n S7 edge.
What the dilly with that Samsung???
I had same problem just fixed it! Hope it works for you. Press on the smart view , but hold on to it , it takes you to a screen that tells you, about smart view, press on that, once you get there you will have a choice to [force stop], press on that. You can now exit and try your smart view now. That should do it.
If that failed, which did for me , go to your smart tv and update software, works really great now.
Get to the about phone part in the settings. Click software information. Then click on build number 7 times, this should turn on developer options. Then from developer options menu,turn on authorize wireless display, and check the boxes inside that option. This is the only thing that worked for me.
I thought you needed to use a USB-C to display port adapter? Or is USB-C to HDMI also supposed to work? I've been using a Samsung dongle connected to a Sony Bravia television and haven't had any trouble getting smart view to work on my Verizon Note 8. I've been using it since day one. Have you tried calling tech ssupport?