Screen - Settings Dirt Procedural Map and Screen - View in Material Editor 
Final Result - All Ok.

Change Radius - Texture

Screen Radius = Texture and Screen View in Material Editor

Final Result = Not Ok. Left side - not changed, result = zero.

Final Result - All Ok.
Change Radius - Texture
Screen Radius = Texture and Screen View in Material Editor
Final Result = Not Ok. Left side - not changed, result = zero.