SFTP连接失败报错'subsystem request failed on channel 0 Connection closed'但SSH连接正常的问题排查求助

大家好，我最近碰到一个挺困扰的问题：当我用以下命令尝试建立SFTP连接时：

sftp user@host

总是收到报错信息：

subsystem request failed on channel 0 Connection closed

但奇怪的是，用SSH命令连接同一台主机却完全正常：

ssh user@host

我把正在使用的完整sshd_config文件内容附在下面（内容有部分截断）：

#       $OpenBSD: sshd_config,v 1.104 2021/07/02 05:11:21 dtucker Exp $

# This is the sshd server system-wide configuration file.  See
# sshd_config(5) for more information.

# This sshd was compiled with PATH=/usr/local/bin:/usr/bin:/usr/local/sbin:/usr/sbin

# The strategy used for options in the default sshd_config shipped with
# OpenSSH is to specify options with their default value where
# possible, but leave them commented.  Uncommented options override the
# default value.

# To modify the system-wide sshd configuration, create a  *.conf  file under
#  /etc/ssh/sshd_config.d/  which will be automatically included below
Include /etc/ssh/sshd_config.d/*.conf

# If you want to change t...

有没有大佬能帮我分析下问题出在哪，该怎么排查解决呢？

备注：内容来源于stack exchange，提问作者Angie