I have a 42pfl6687 which sometimes needs a reboot (off/on button on the back) to get rid of the 'server not found' message. At these times the TV has a proper IP and DHCP configuration. I checked this both in the TV network settings and in my router/modem. TV is connected through wired ethernet.

According to Philips support I should enable 'cloud service' in my router. I have never heard of such an option. Is there a specific configuration (e.g. forwarded ports) required for smart TV to keep working after standby?