Every time I add ground ginger it's a mistake

Maybe I'm using too much. Maybe my conception of its flavour is wrong and fresh ginger would work. Example: vegetables (onion, celery, garlic, carrots, etc, plus squash/potato) lightly coated in olive oil and a splash of soy sauce and dusted with black pepper (sometimes chili flake too) and roasted. It's no culinary masterpiece but it's palatable. Adding ground ginger, however, makes for a pasty sauce that is much less palatable despite having little ginger flavour.