buffering here too. I am in the United Kingdom on a fibre optic cable at 50mbps accessing from firefox browser on windows 10. The computer is a Thinkpad Workstation with I7 quadcore. I can stream 4k video without any buffering so an mp3 file should not buffer, however the internet is made up of a ton of computers so likely it is a network issue somehere along the line

edit: your demo page eventually causes firfox to crash, however it works fine on Edge.