Running ipa-server-install --uninstall -U -v --forceom  5.8.18-300.fc33.x86_64 results in the following. Note we did change the hostname and IP address since the original installation.
Loading StateFile from '/var/lib/ipa/sysrestore/sysrestore.state'
Removing IPA client configuration
Starting external process
args=['/usr/sbin/ipa-client-install', '--on-master', '--unattended', '--uninstall']
Unconfigured automount client failed: CalledProcessError(Command ['/usr/sbin/ipa-client-automount', '--uninstall', '--debug'] 
returned non-zero exit status 1: 'Loading StateFile from 
'/var/lib/ipa-client/sysrestore/sysrestore.state\'
Loading StateFile from \'/var/lib/ipa-client/sysrestore/sysrestore.state\'
Loading StateFile from \'/var/lib/ipa-client/sysrestore/sysrestore.state\
Starting external process
args=[\'/usr/bin/authselect\', \'disable-feature\', \'with-custom-automount\']
Process finished, return code=2
stdout=
stderr=Unable to disable feature [2]: No such file or directory
Traceback (most recent call last):
File "/usr/sbin/ipa-client-automount", line 27, in <module>
    main()
  File "/usr/lib/python3.9/site-packages/ipaclient/install/ipa_client_automount.py", line 600, in main
    configure_automount()\n  File "/usr/lib/python3.9/site-packages/ipaclient/install/ipa_client_automount.py", line 473, in configure_automount
    return uninstall(fstore, statestore)
  File "/usr/lib/python3.9/site-packages/ipaclient/install/ipa_client_automount.py", line 322, in uninstall
    tasks.disable_ldap_automount(statestore)\n  File "/usr/lib/python3.9/site-packages/ipaplatform/redhat/tasks.py", line 776, in disable_ldap_automount
    ipautil.run(authselect_cmd)
  File "/usr/lib/python3.9/site-packages/ipapython/ipautil.py", line 594, in run
    raise CalledProcessError(ipapython.ipautil.CalledProcessError: CalledProcessError(Command [\'/usr/bin/authselect\', \'disable-feature\', \'with-custom-automount\'] returned non-zero exit status 2: \'Unable to disable feature [2]: No such file or directory\
\')
')
NSS is built without support of the legacy database(DBM)
The ipa-client-install command failed. See /var/log/ipaclient-uninstall.log for more information
Process finished, return code=1
Uninstall of client side components failed!
  File "/usr/lib/python3.9/site-packages/ipapython/admintool.py", line 180, in execute
    return_value = self.run()
  File "/usr/lib/python3.9/site-packages/ipapython/install/cli.py", line 340, in run
    return cfgr.run()
  File "/usr/lib/python3.9/site-packages/ipapython/install/core.py", line 360, in run
    return self.execute()
  File "/usr/lib/python3.9/site-packages/ipapython/install/core.py", line 386, in execute
    for rval in self._executor():
  File "/usr/lib/python3.9/site-packages/ipapython/install/core.py", line 431, in __runner
    exc_handler(exc_info)
  File "/usr/lib/python3.9/site-packages/ipapython/install/core.py", line 460, in _handle_execute_exception
    self._handle_exception(exc_info)
  File "/usr/lib/python3.9/site-packages/ipapython/install/core.py", line 450, in _handle_exception
    six.reraise(*exc_info)
  File "/usr/lib/python3.9/site-packages/six.py", line 703, in reraise
    raise value
  File "/usr/lib/python3.9/site-packages/ipapython/install/core.py", line 421, in __runner
    step()
  File "/usr/lib/python3.9/site-packages/ipapython/install/core.py", line 418, in <lambda>
    step = lambda: next(self.__gen)
  File "/usr/lib/python3.9/site-packages/ipapython/install/util.py", line 81, in run_generator_with_yield_from
    six.reraise(*exc_info)
  File "/usr/lib/python3.9/site-packages/six.py", line 703, in reraise
    raise value
  File "/usr/lib/python3.9/site-packages/ipapython/install/util.py", line 59, in run_generator_with_yield_from
    value = gen.send(prev_value)
  File "/usr/lib/python3.9/site-packages/ipapython/install/core.py", line 655, in _configure
    next(executor)
  File "/usr/lib/python3.9/site-packages/ipapython/install/core.py", line 431, in __runner
    exc_handler(exc_info)
  File "/usr/lib/python3.9/site-packages/ipapython/install/core.py", line 460, in _handle_execute_exception
    self._handle_exception(exc_info)
  File "/usr/lib/python3.9/site-packages/ipapython/install/core.py", line 518, in _handle_exception
    self.__parent._handle_exception(exc_info)
  File "/usr/lib/python3.9/site-packages/ipapython/install/core.py", line 450, in _handle_exception
    six.reraise(*exc_info)
  File "/usr/lib/python3.9/site-packages/six.py", line 703, in reraise
    raise value
  File "/usr/lib/python3.9/site-packages/ipapython/install/core.py", line 515, in _handle_exception
    super(ComponentBase, self)._handle_exception(exc_info)
  File "/usr/lib/python3.9/site-packages/ipapython/install/core.py", line 450, in _handle_exception
    six.reraise(*exc_info)
  File "/usr/lib/python3.9/site-packages/six.py", line 703, in reraise
    raise value
  File "/usr/lib/python3.9/site-packages/ipapython/install/core.py", line 421, in __runner
    step()
  File "/usr/lib/python3.9/site-packages/ipapython/install/core.py", line 418, in <lambda>
    step = lambda: next(self.__gen)
  File "/usr/lib/python3.9/site-packages/ipapython/install/util.py", line 81, in run_generator_with_yield_from
    six.reraise(*exc_info)
  File "/usr/lib/python3.9/site-packages/six.py", line 703, in reraise
    raise value
  File "/usr/lib/python3.9/site-packages/ipapython/install/util.py", line 59, in run_generator_with_yield_from
    value = gen.send(prev_value)
  File "/usr/lib/python3.9/site-packages/ipapython/install/common.py", line 73, in _uninstall
    for unused in self._uninstaller(self.parent):
  File "/usr/lib/python3.9/site-packages/ipaserver/install/server/__init__.py", line 581, in main
    uninstall(self)
  File "/usr/lib/python3.9/site-packages/ipaserver/install/server/install.py", line 272, in decorated
    func(installer)
  File "/usr/lib/python3.9/site-packages/ipaserver/install/server/install.py", line 1261, in uninstall
    sys.exit(rv)
DEBUG The ipa-server-install command failed, exception: SystemExit: 1