Can't open some websites?

I have recently had the problem that I can no longer open some websites on my laptop (Windows 10). Google and YouTube work e.g. No problem, but turn on a radio live stream, Firefox updates, Discord and some websites don't work. My cell phone and tablet are in the same Wi-Fi and everything works there.

Can someone help me and tell me what it is?

Vlt. A security software that blocks something.

If something does not work on the PC, there are usually more or less meaningful error messages. You should give them a chance, literally.

Then temporarily deactivate a virus scanner and try again.

Is that the scapegoat?

if that's not enough, go to the user account control and pull the slider all the way down

No, there are unfortunately no error messages here. Some websites can be loaded basically, but hardly work. Some things like Spotify, Discord can't be loaded at all - that means "You are offline"… And YouTube works perfectly again.

Does not work too…

Tested… Unfortunately it is not because of that.

Jo, then, as someone wrote, an unfavorable virus protection setting can be the reason.

I have completely deactivated virus protection… But I still can't.

Disable the windows firewall let's see that

Just an idea:

Maybe the router Speedlink 5501 in the house?

If so, it has a software error in the DHCP server. It doesn't let new devices properly into the network.

In such a case I have described the solutions here:

Why is the Wi-Fi only partially (Android cell phone and PC)? (Internet, Samsung, router) - good question