TV problem with Wi-Fi?

I have a problem with my LG Smart TV. Videos on YouTube do not load on this television. All other videos e.g. B. Load from a media library as normal. If I go to the television with another device (laptop) and want to start a video, it works without any problems. In addition, it is the case with the television that when you turn it on there are 2 options. Either the Wi-Fi is working fine or it is not working. If you then turn off the TV and turn it on again after 10 minutes, it usually works again. The connection with a LAN cable did not help either. And by the way, the television is about 11 meters away from the Wi-Fi router. There's also a repeater next to the television. This has brought about an improvement that now every device in the room has Wi-Fi… Except for the television. Can anyone help me further?

Can I do a system update on this TV? If all else fails, I would reset the TV to factory settings and set it up again.

To clarify where the problem is:

You open the YouTube SmartTV app with the remote control and start any video. The video player opens, but no video is played because it can't be loaded.

If you use the YouTube "Cast" function on your laptop, the video will play without any problems. Or do you connect your laptop via HDMI and play the video via the laptop browser? In this case, your SmartTV is just a dumb screen.

All other SmartTV apps such as Prime Video, Netflix or the ARD media library run without problems?

For me, it's not an internet connection. Browsing through YouTube or the other apps also requires Wi-Fi or internet.

Is there a YouTube app update in the LG content store? A possibly existing system update could also help.