Update Router.java

core/src/mindustry/world/blocks/distribution/Router.java

@@ -23,6 +23,11 @@ public class Router extends Block{
         noUpdateDisabled = true;
     }
 
+    public boolean canReplace(Block other){
+        if(other.alwaysReplace) return true;
+        return (other != this || rotate) && this.group != BlockGroup.none && other.group == this.group;
+    }
+
     public class RouterBuild extends Building implements ControlBlock{
         public Item lastItem;
         public Tile lastInput;