Hi, I have the Vigor2762ac and with Firmware is 3.8.8.2, all devices that played YouTube without stalling / buffering now, once connected to Vigor2762ac wifi on either 2.5GHz or 5 Ghz now stalling / buffering on playback. I have spent the day going through the forum and tried changing channels, enable / disabling 5 GHz, the issue persists. Any suggestions welcome and thanks for taking the time to reply.

[Firewall] > [Defense Setup] and if UDP Flood Defense is enabled, try disabling, this worked for me. Will now see if any settings work and allow me to keep this ticked.

Thanks to admin3 who suggested this in the post Re: Vigor 2820 and BT Infinity DNS issue