Did OpenSea Remove Creator Royalties?

Probably, but no official announcement yet. Starting on Apr 4, zero royalty trades on OpenSea shot up. Since Feb 17, OpenSea's stated policy is enforcing 0.5% royalties on old contracts with non-zero royalties. The below data suggests an unannounced change. Note: Some projects actually have 0% royalties (e.g. ENS). Therefore, I use a basket of high volume, older projects with non-zero royalties.