You guys need to switch to server-side tracking instead of relying on browser pixels. I had the same problem until I implemented Conversion API which sends data directly from your server to Facebook bypassing all the browser restrictions. You can see CAPI setup guides that walk through the whole process step by step. Now Facebook gets all my conversion data even when customers have privacy settings enabled. My attribution went from maybe 40% accuracy to nearly 100% which makes campaign optimization actually possible again instead of just guessing