Use str_replace for finding actual file names

includes/Checker/Checks/Plugin_Repo/File_Type_Check.php

@@ -264,7 +264,7 @@ protected function look_for_badly_named_files( Check_Result $result, array $file
 
 		$files = array_map(
 			function ( $file ) use ( $plugin_path ) {
-				return substr( $file, strlen( $plugin_path ) );
+				return str_replace( $plugin_path, '', $file );
 			},
 			$files
 		);