I DH just after high krausen. In my attempt to brew the perfect hazy IPA, my first several batches were dry hopped very late, close to bottling. I experienced oxidation issues on more than half. After several more batches I’ve perfected (for my process) a hop schedule of 5 minutes, hop stand and DH after high krausen, which seemed to have remedied the oxidation issue and has also perfected the bitterness/hoppiness balance for my taste.