tl;dr: AliExpress silently loads two obfuscated Alibaba anti-fraud scripts (collina.js and fireyejs.js) that create hidden WebAudio graphs — a sawtooth oscillator routed through an analyser and zero-gain node to the audio destination — as part of a broader browser fingerprint covering canvas, WebGL, hardware, and interaction data. Because the graph is connected to the system audio output (despite being silent), it keeps the PC's Bluetooth audio path active, breaking multipoint headphone switching to other devices. Blocking the two scripts via uBlock Origin filters stops the behavior, though it may trigger additional CAPTCHAs.