@mekus2x Hi, do you mean youtube website or youtube app? or both? and does it happen on all client devices? Please check if you enabled parental control on the router, if not, try connecting the same...

@iakko Hi, To assist you efficiently, I've forwarded your case to the TP-Link support engineers who will contact you with your registered email address later. Please pay attention to your email box...

@Fernando2112 You are welcome~

@Gremnet OK, please let us know the testing results once you have any update.

@Cristian77 Hi, is your smartphone Android phone or iPhone? Please check if the issue is the same as this thread: Some client devices have no internet access such as Android devices or Chromecast...

@Yusufkvn Hi, please check if the solution mentioned in this thread works for you or not: 'Authentication failed, Server TLS version is too low' appears when connecting OpenVPN of DSL Modem