MUST FIX in HLS mediastreamvalidator: Discontinuity sequence numbers not aligned

Does anyone know what do these errors mean ? By looking at m3u8, nothing seem obvious

Error: Discontinuity sequence numbers not aligned --> Detail: Missing leading domains --> Source: /backup/mastervideo-h264-240p-30fps.m3u8

--> Detail: Extra trailing domains --> Source: /backup/mastervideo-h264-240p-30fps.m3u8

Thanks