I experience frequent "network connection lost" problems - without using DLNA at all.
For me, i It happens just by watching a channel which includes HbbTV information (Danish TV DR1) .
Often, when the tv gets HbbTV info to show the "DR.NU (red dot)" logo in lower right corner, it will blank out the screen and show a [1[2[3 Connecting... STOP]]] panel. Sometimes it briefly shows a message about "network connection lost" (in Danish) first. But the common thing is that this pop-up never disappears by itself - I have to press OK to confirm the STOP button.
The TV then goes completely black for 2 secs before returning to the channel/program I was watching.
So I think the problem lies deeper than DLNA -- it's at the root of the network stack or interface(s) affecting all services using the network. Insanely annoying for a "net tv" !
55pfl8007T/12 (150.82).
Good WiFi connection 54 Mbps -- tried with static IP and DHCP settings - happens with both.

