ASP.net "data-dark-logo" not working

Because "data-dark-logo = "~/images/canvasone-dark@2x.png" was not working in my ASP.net html code.
Maybe the reason is the '~'-sign I have to use to find the file on every page.

I tried to switch it to the <picture> Tag.
But it still not work with "media="(prefers-color-scheme: dark)"".
If I tried it for testing with "media="(min-width: 600px)"" and the right picture shows up.

Here is the Code:

     
     WORKING-->
   
![attachment](~/images/canvasone.png)

Have you an idea what the problem could be.

Kind Regards

Manuel