bash将输出重定向到文件但结果不完整

The question of redirecting output of a command was already asked many times, however I am having a strange behavior. I am using a bash shell (debian) with version 4.3.30(1)-release and tried to redirect output to a file, however not everything are logged in the file. The bin file that I tries to run is sauce-connectv4.4.1 for linux (client of saucelabs that is publicly available in internet)The question of redirecting output of a command