WSL instance keeps stopping despite imp initialized

[jellium]

Current /etc/wsl.conf config file (see the [boot] section):

[automount]
enabled = true
root = /mnt
options = "metadata,uid=1000,gid=1000,umask=077,fmask=11,case=off"
mountFsTab = true

[boot]
systemd = true
command = imp --initialize

[user]
default = jellium

[interop]
enabled = false
appendWindowsPath = false

After startup, ps aux|grep imp returns:

root         674  0.0  0.0   2576   900 ?        Ss   01:24   0:00 /bin/sh /usr/lib/bottle-imp/wait-forever.sh
jellium        978  0.0  0.0   6332  1988 pts/0    S+   01:25   0:00 grep --color=auto --exclude-dir=.bzr --exclude-dir=CVS --exclude-dir=.git --exclude-dir=.hg --exclude-dir=.svn --exclude-dir=.idea --exclude-dir=.tox imp

However, when closing all terminal windows of this WSL instance, wsl --list --verbose returns after ca. 15 seconds:

  NAME      STATE           VERSION
* Debian    Stopped         2

What am I missing?
Thank you.