PROPFIND shows external storage that is not available

Steps to reproduce

1. Create a new user
2. Using the occ command create a new external storage mount

sudo -u www-data ./occ files_external:create ext2 local null::null -c datadir=tests/acceptance/ext2

3. Upload a file to the external storage using the webdav api

curl -XPUT http://localhost/core/remote.php/webdav/ext2/file.txt -u tu1:tu1 -d "hello" -vk 

4. rename the external storage folder to a different name on the file system where it is mounted to owncloud ( to make the folder unavailable for owncloud)
5. Use PROPFIND to get the contents in the external storage folder

 curl -XPROPFIND http://localhost/core/remote.php/webdav/ext2 -u tu1:tu1  | xmllint --format -

note this behavior is not shown if the user is logged so it is only reproduced when the steps are done through api and cli only.

Expected behaviour

return 404 with message the folder is not available

Actual behaviour

gives 207 and returns the content of the old folder

Server configuration

Operating system: ubuntu 20.04

Web server: apache2

Database: sqlite

PHP version: 7.4

ownCloud version: (see ownCloud admin page) git-master

Updated from an older ownCloud or fresh install: fresh

Where did you install ownCloud from: git

Start by reproducing the issue with the listed occ command and PROPFIND request against the external storage mount. Trace the WebDAV PROPFIND handling and external-storage availability checks mentioned by the reproduction; done means an unavailable mount returns 404 with an unavailable-folder message instead of 207 and stale content.