Model: 40PFL7605H/12. Firmware version:

Using several DLNA servers on my PC (Serviio, Windows Media Player, etc.. ), I had found the following issue: streaming a movie is impossible; all is ok at first, but about 20/25 minutes it seems that TV loses wifi-connection (it's annoying, with TV entering "configure network menus" again, or showing black screen). I think is related to TV, as dropping wifi-connection. I put my wifi router closer, but it keeps happening.
Is this happening to someone else??