I had the same exact issue. Tried it all. Yet I simply remembered I had my tv connected to the internet via LAN (hard wire) instead of wifi.
I then made sure both my phone and my tv were connected via the same exact Wifi network.
Now also in my case my Comcast/Xfinity router has 2 wifi settings . My phone can only connect to wifi 1 but my ps4 and tv can connect to wifi 1 and wifi 2. So if that's the case make sure you are connected to the right one.
Now my smart view is working fine
I have an s8+ and 2 Samsung series 6 smart TVs.
I literally had my phone connected to my TV yesterday. Today smart view doesnt even show either of TVs.
I can use my phone as a remote to operate both TVs, but I cannot use smart view to watch videos from my phone.
I don't know what's going on.
Thank you so much!! I've been trying to mirror screen for weeks. It was working fine before and out of nowhere it wouldn't register. I was only able to use the remote control. I looked everywhere online for a solution and this finally worked. Finally!!
Thanks for posting