Same spaghetti sauce recipe for over 30 years
I'm assuming multiple people are tasting the acidity.
Different tinned tomatoes can have widely different acidity. These seem like a much more likely source for acid than any other ingredient, even the red wine. The soup is likely to be fairly neutral. The onion, garlic (and probably other soffrito) are somewhat alkaline. Can't imagine you've lacto-fermented your chicken broth or your meatballs.
OT but there's some great threads on balancing acidity already.