Why can't I change the anisotropic filter at runtime?

I tried searching for this everywhere, but I didn't find anything helpful sadly. I am programming my settings menu (in the main menu) of my game project, and I created a slider for anti-aliasing (which works perfectly) and one for anisotropic filtering. The AA slider works, the AF doesn't, even though the two are almost identical. What am I doing wrong? Even the scripting docs tell me that I should write it this way...

Here is my piece of code:

 switch((int)g_AASlider){
         case 0:
             QualitySettings.antiAliasing = 0; 
             AA_dispString = AAStrings[0];
             break;
         case 1:
             QualitySettings.antiAliasing = 2; 
             AA_dispString = AAStrings[1];
             break;
         case 2:
             QualitySettings.antiAliasing = 4; 
             AA_dispString = AAStrings[2];
             break;
         case 3:
             QualitySettings.antiAliasing = 8; 
             AA_dispString = AAStrings[3];
             break;
         }
         
         switch((int)g_AFSlider){  //FIX ME PLS
         case 0:
             QualitySettings.anisotropicFiltering = AnisotropicFiltering.Disable; 
             AF_dispString = AFStrings[0];
             break;
         case 1:
             QualitySettings.anisotropicFiltering = AnisotropicFiltering.Enable; 
             AF_dispString = AFStrings[1];
             break;
         case 2:
             QualitySettings.anisotropicFiltering = AnisotropicFiltering.ForceEnable; 
             AF_dispString = AFStrings[2];
             break;
         }

(the switch cases refer to the typecasted int returned by the slider, and the string array displays on the screen which option is currently selected)

I really hope somebody can help me :)