Safari 15.1 has a critical regression that crashes the tab when a video track is muted and H.264 is in use, affecting p2p calls made with daily-js users. This issue only affects Safari on both MacOS and iOS, specifically when browsers negotiate H.264 or developers override to force H.264 without certain conditions being met. To mitigate this regression, daily-js automatically works around it by using VP8 for outgoing tracks, while customers who explicitly force H.264 can work with the team to ensure their application isn't impacted. This change is expected to make applications more stable and will be transparent to most Daily customers and their users.