http://fa-ir.facebookwkhpilnemxj7asaniu7vnjjbiltxjqhye3mhbshg7kx5tfyd.onion/business/help/165119026899353?ref=fb4b_adsmanager_products
Once you change any element of your campaign, the new version replaces the old one. There’s no option to reverse changes and no way to distinguish between the metrics from before and after edits are made. When you edit your ad, you won’t lose engagement (likes, comments and shares) from before your ad was edited, unless you: Change images, videos or text.