I'm perplexed by your reply; I definitely mean (black|carbon) steel and note it is lighter than cast iron. Never a problem making a pan sauce in a black steel pan.
Stainless steel or enameled cast iron is my choice for long cooking tomato sauces, although even plain aluminum won't be an issue for a few minutes contact.
My experience with pan sauces in carbon steel is that the acid in wine will typically start to strip the seasoning and leave ugly black specks in your sauce.
You are not doing anything wrong. Liquids with higher acidity will strip the seasoning. Avoid cooking liquids with tomato, lemon juice, wine, vinegar etc..for long slow braises and pan sauces etc.
