@alexs77 Hi,
not much to do about this - some sites capture keyboard input for their own use. And some sites do it stupidly - wholly ignorant about browsers like Vivaldi where users can assign their own hotkeys.
The only workaround in such cases is to add alternate hotkeys for some things. For instance, Ctrl+PageUp/PageDown is an alternative for cycling tabs in most browsers, also in Vivaldi. Ctrl+Tab also works. I guess on MacOS Ctrl=Cmd?
When it comes to Ctrl+L to focus the url field the standard in all other browsers is Alt+D - Vivaldi has inherited some hotkeys from old Opera.
F8 is also default in Vivaldi, but the WDR site seems to have overridden that to Play/Pause.
For instance the WDR site seems to assign Ctrl+number like YouTube and others do to jump to a specific point in the stream.
One could argue the browser should always prioritize its own keyboard hotkeys over any the site assigns, but then that would cause problems for users who expect some hotkeys to work on sites.