hp-plugin fails for ScanJet Pro 2000 s2

Hi all, I'm currently using Kubuntu 21.04.

I'm trying to setup my ScanJet Pro 2000 s2 (connected via usb) and installed hplip-3.21.8.run according to the instructions here: https://developers.hp.com/hp-linux-imaging-and-printing/install/install/index

The installation works fine until it tries to setup the scanner itself in Step 13. After replugging the USB-cable, it gets detected without problems. Then, both options of the driver plugin-installer fail though:
- When trying to download the plug-in from the HP server, following error is thrown in the terminal:

Checking for network connection...
Downloading plug-in from:
Traceback (most recent call last):
  File "/usr/share/hplip/base/password.py", line 85, in get_distro_name
    os_name = platform.dist()[0]
AttributeError: module 'platform' has no attribute 'dist'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/share/hplip/ui5/plugindialog.py", line 248, in NextButton_clicked
    status, download_plugin_file, error_str = self.pluginObj.download(self.plugin_path,self.plugin_download_callback)
  File "/usr/share/hplip/installer/pluginhandler.py", line 257, in download
    core = core_install.CoreInstall()
  File "/usr/share/hplip/installer/core_install.py", line 241, in __init__
    self.passwordObj = password.Password(ui_mode)
  File "/usr/share/hplip/base/password.py", line 118, in __init__
    self.__readAuthType() # self.__authType
  File "/usr/share/hplip/base/password.py", line 141, in __readAuthType
    distro_name = get_distro_name().lower().replace(" ","")
  File "/usr/share/hplip/base/password.py", line 88, in get_distro_name
    os_name = distro.linux_distribution()[0]
  File "/usr/lib/python3/dist-packages/distro.py", line 125, in linux_distribution
    return _distro.linux_distribution(full_distribution_name)
  File "/usr/lib/python3/dist-packages/distro.py", line 681, in linux_distribution
    self.version(),
  File "/usr/lib/python3/dist-packages/distro.py", line 741, in version
    self.lsb_release_attr('release'),
  File "/usr/lib/python3/dist-packages/distro.py", line 903, in lsb_release_attr
    return self._lsb_release_info.get(attribute, '')
  File "/usr/lib/python3/dist-packages/distro.py", line 556, in __get__
    ret = obj.__dict__[self._fname] = self._f(obj)
  File "/usr/lib/python3/dist-packages/distro.py", line 1014, in _lsb_release_info
    stdout = subprocess.check_output(cmd, stderr=devnull)
  File "/usr/lib/python3.9/subprocess.py", line 424, in check_output
    return run(*popenargs, stdout=PIPE, timeout=timeout, check=True,
  File "/usr/lib/python3.9/subprocess.py", line 528, in run
    raise CalledProcessError(retcode, process.args,
subprocess.CalledProcessError: Command '('lsb_release', '-a')' returned non-zero exit status 1.
Error in sys.excepthook:
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/apport_python_hook.py", line 153, in apport_excepthook
    with os.fdopen(os.open(pr_filename,
PermissionError: [Errno 13] Permission denied: '/var/crash/_usr_share_hplip_plugin.py.1000.crash'

Original exception was:
Traceback (most recent call last):
  File "/usr/share/hplip/base/password.py", line 85, in get_distro_name
    os_name = platform.dist()[0]
AttributeError: module 'platform' has no attribute 'dist'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/share/hplip/ui5/plugindialog.py", line 248, in NextButton_clicked
    status, download_plugin_file, error_str = self.pluginObj.download(self.plugin_path,self.plugin_download_callback)
  File "/usr/share/hplip/installer/pluginhandler.py", line 257, in download
    core = core_install.CoreInstall()
  File "/usr/share/hplip/installer/core_install.py", line 241, in __init__
    self.passwordObj = password.Password(ui_mode)
  File "/usr/share/hplip/base/password.py", line 118, in __init__
    self.__readAuthType() # self.__authType
  File "/usr/share/hplip/base/password.py", line 141, in __readAuthType
    distro_name = get_distro_name().lower().replace(" ","")
  File "/usr/share/hplip/base/password.py", line 88, in get_distro_name
    os_name = distro.linux_distribution()[0]
  File "/usr/lib/python3/dist-packages/distro.py", line 125, in linux_distribution
    return _distro.linux_distribution(full_distribution_name)
  File "/usr/lib/python3/dist-packages/distro.py", line 681, in linux_distribution
    self.version(),
  File "/usr/lib/python3/dist-packages/distro.py", line 741, in version
    self.lsb_release_attr('release'),
  File "/usr/lib/python3/dist-packages/distro.py", line 903, in lsb_release_attr
    return self._lsb_release_info.get(attribute, '')
  File "/usr/lib/python3/dist-packages/distro.py", line 556, in __get__
    ret = obj.__dict__[self._fname] = self._f(obj)
  File "/usr/lib/python3/dist-packages/distro.py", line 1014, in _lsb_release_info
    stdout = subprocess.check_output(cmd, stderr=devnull)
  File "/usr/lib/python3.9/subprocess.py", line 424, in check_output
    return run(*popenargs, stdout=PIPE, timeout=timeout, check=True,
  File "/usr/lib/python3.9/subprocess.py", line 528, in run
    raise CalledProcessError(retcode, process.args,
subprocess.CalledProcessError: Command '('lsb_release', '-a')' returned non-zero exit status 1.

When selecting the option to install a local copy of the file (what I don't have anyways I think), the following error is thrown:

kf.kio.core: KIO Connection server not listening, could not connect
kf.kio.core: couldn't create slave: "Can not create socket for launching io-slave for protocol 'tags'."
kf.kio.core: "Unable to create io-slave. Can not create socket for launching io-slave for protocol 'tags'."
kf.kio.core: KIO Connection server not listening, could not connect
kf.kio.core: couldn't create slave: "Can not create socket for launching io-slave for protocol 'file'."
kf.kio.core: KIO Connection server not listening, could not connect
kf.kio.core: couldn't create slave: "Can not create socket for launching io-slave for protocol 'file'."
kf.config.core: Couldn't write "/home/lukas/.config/kdeglobals" . Disk full?
kf.config.core: Couldn't write "/home/lukas/.config/hp-pluginrc" . Disk full?

The disk is definitely not full with ~1.5TB unused space.
Running hp-plugin yields the same result.
Connecting to the scanner via xSane or skanlite afterwards fails with an Error during device I/O.

Any help is appreciated, thanks in advance.