Crossing a breakpoint moves the player to another branch of the stream page's layout, which remounted the <video> and the hls.js/WebRTC session feeding it, so every resize reloaded the stream. A VideoHostProvider near the top of the web app now renders each player's video (keyed to its player store) and moves the DOM node into the player's <HostedVideo> slot. A slot that remounts picks up the same playing element. Native is unchanged.