Hello,
Based on your description, my understanding is that there is no smart-TV option when right click medial file and try to open it with "Stream to Device".
Please make sure media stream is turned on via:
Control Panel \ Network and Internet\ Network and Sharing Center
Then, open Windows Media Player, right click the file and choose the option Play to device. And confirm that if you can choose the smart TV.
Also, please make sure the smart TV supports DLNA.
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