Unable to cast content from phone to smart TV

I have a Moto G5+ phone, running Android version 7.o. I have been trying to send content from the phone to a Samsung smart TV. However, when I open the settings page for the Cast function, the TV doesn't show up as an available target.

The TV has been properly set up as a WiFi device on my network. I gave it a recognizable device name, and the TV settings confirm that it is connected to the network.

I can connect to the internet with the browser function in the TV.

The TV shows up in the Windows (Windows 7) network app. In fact, the network app shows three icons for the same TV. Once under "Media Devices", and two more icons under "Other Devices" (why two?). All three instances include the name I assigned to the TV in the TV settings.

I have set the source mode in the TV settings to "screen mirroring", which I take to be the correct mode for accepting content from the phone.

Despite all of the above, the phone doesn't seem to be able to see the TV. What am I missing here? The only thing I can think of is that this particular phone model doesn't support the Cast function?

 

I did a little messing around, based on the first link in your reply. No success yet, but it looks like the answer will involve properly setting up both the phone and the TV for WiFi direct mode. Managed to get the TV to see the phone, but the phone still doesn't see the TV.

Too hot around here for science projects. Will give it another go in the morning.

(By the way, you seem to pop up everywhere with good advice. When you you ever sleep?