Comment 9 for bug 1927742

I've just replicated your steps with a vm booted into ubuntu-20.04.6-desktop-amd64.iso and there are no problems with webdav for me aside for the bug reported:

(I ssh into the vm so when I say "copy-paste" it is literally that)

### install the stuff
- enable the universe repo in /etc/apt/sources.list
- sudo apt update
- sudo apt install apache2 dolphin
### configure apache
- sudo a2enmod dav dav_fs
- copy-paste your apache vhost config into /etc/apache2/sites-available/test.conf
- sudo a2ensite test.conf
- sudo systemctl restart apache2
### webdav dir
- sudo mkdir -p /var/www/webdav
- sudo chown www-data: /var/www/webdav

Now in dolphin, press C-l and enter path "webdav://localhost". There I can create files and dirs, delete files, but not delete dirs.

--

Try enabling the logs. Put these lines (as per /etc/apache2/sites-enabled/000-default.conf) into your test.conf:

    ErrorLog ${APACHE_LOG_DIR}/error.log
    CustomLog ${APACHE_LOG_DIR}/access.log combined

and restart apache. And keep looking under /var/log/apache2/