为何subprocess.check_output执行远程systemctl命令返回非零退出状态3？

我需要检查QEMU实例（标准连接方式为ssh root@192.168.7.2）上<SERVICE>的状态：

命令行执行正常 #

直接在命令行执行以下命令：

sshpass -p none ssh -o StrictHostKeyChecking=no root@192.168.7.2 -t 'systemctl is-active <SERVICE>'

能得到预期输出：

failed

使用subprocess.check_output执行报错 #

但用Python的subprocess.check_output执行相同命令时：

subprocess.check_output("sshpass -p none ssh -o StrictHostKeyChecking=no root@192.168.7.2 -t 'systemctl is-active <SERVICE>'", shell=True, encoding='utf8', stderr=subprocess.DEVNULL)

会抛出如下错误：

Traceback (most recent call last):
  File "", line 1, in 
  File "/usr/lib/python3.8/subprocess.py", line 415, in check_output
    return run(*popenargs, stdout=PIPE, timeout=timeout, check=True, 
  File "/usr/lib/python3.8/subprocess.py", line 516, in run
    raise CalledProcessError(retcode, process.args,
subprocess.CalledProcessError: Command 'sshpass -p none ssh -o StrictHostKeyChecking=no root@192.168.7.2 -t 'systemctl is-active <SERVICE>'' returned non-zero exit status 3.

其他命令执行正常 #

用相同代码执行其他命令（如echo $PATH）时，subprocess.check_output能得到预期输出：

'/usr/bin:/bin:/usr/sbin:/sbin\n'

请问为何subprocess.check_output与systemctl配合时无法正常工作？

内容的提问来源于stack exchange，提问作者DonnyFlaw