One of the devices on the network is a Samsung TV. Most of the apps work on it (Amazon etc), but Netflix will load and let you search but won’t play anything (if you put the TV on another network it works fine). It just spins endlessly. Tried all the updating I can.
Oddly Netflix will play via a tablet or Mac connected to the RUTX12.
I assume the RUTX12 is on the latest firmware version. Correct?
Could you try the following:
On the TV, check the network settings and try setting a manual DNS server to 8.8.8.8 or 1.1.1.1.
On the RUTX12, navigate to Network → Firewall → General and try disabling ‘software flow offloading’.
On the RUTX12, navigate to Network → Interfaces → edit mob1s1a1 interface (or whichever is used for mobile connect) → Advanced settings. There, try setting an MTU manually. You can try different values, such as 1440, 1360, 1260, etc. Or you can access the command line of the device and execute the following command to see what MTU values to try:
gsmctl -A ‘AT+QMTUINFO’
If none of the above helps, could you please provide details on how everything is connected and whether the issue is only with the Netflix App and only on the TV?