playing a livestream error -12888

I play livestream thì bị lỗi : -12888 -"Playlist File unchanged for longer than 1.5 * target duration" , I also read error -12888 in the documentation page 170: https://docs.huihoo.com/apple/wwdc/ 2018/502_measuring_and_optimizing_hls_performance.pdf but still don't understand the reason. Please explain to me the reason for the error?