For shits and grins I've been perusing the owner's manual
for your TV, and I don't think it supports DLNA. You called Vizio and "confirmed with Vizio that it is DLNA compatible & It will play AVI & MP4 videos via a USB memory stick". The problem is playing things over DLNA and playing things from a thumb drive are two completely different things. I think you were just the victim of the same issue with when you asked for help from the router people, on in this case the Vizio rep is mistaking DLNA for their file playback features. It's very telling I can do a search of the entire manual for the TV and not find the phrase "DLNA" once.
Also, I saw these restrictions on the manual:
- The USB thumb drive must be formatted as FAT32.
- Files on the USB thumb drive must end in a supported file extension (.mp3, .jpg, etc).
- The player is not designed to play media from external hard drives or mp3 players.
Note that there are no video formats mentioned. Also check out page 35 in the manual. There is a "Browse Music" button on the left of the interface that is used to "Toggle photos and music" (probably changes to "Browse Photos" when you're on the other side). Once again, no mention of videos. You might want to stick an actual mp4 video file on a flash drive and see if they were telling you the truth about even that. I recently had the opportunity to mess around with a Vizio blu-ray player at a friend's house. It had an Ethernet port and a USB port and said you could play back media on it, but we never could figure out how to get it to display any of the video files we had on the flash drive I'd brought with me.
Might want to check if there are additional "apps" you can download and add to the VIA widget, maybe DLNA is a feature you have to add separately.
If you decide to call Vizio back, ask them some really specific DLNA questions and you'll probably trip them up. Questions like "can I use more than one PC to stream files to my TV?" or "what's the recommended server software for DLNA?". If your TV supports DLNA they should be able to tell you what container formats, video codecs, and audio codecs are supported in video files. Something else that I noticed is not mentioned at all in your manual.
In any case, if it doesn't work out you can just get a BD player that DOES support DLNA for under a hundred easily to use with your TV.