When someone buys from you, Meta should hear about it two ways: through the browser pixel (in their browser) and through the Conversions API (from your server). Right now the server-side path is only sending 38% of what the browser sees.
For a DTC beverage brand, iOS users are usually a big share of your buyers — and they're the ones Apple's privacy changes block hardest. Meta is optimizing your bids on roughly half your actual purchase data. The fix is a Shopify integration that takes about 90 minutes. After 14 days, expect reported ROAS to climb 5–15%.