Recover external storage with encryption

Please help us by providing the following info. Before posting please also check the pinned "Known issues" threads and make sure that you're running the latest available version for your oC release: https://owncloud.org/changelog/

Steps to reproduce
1. Enable server-side encryption and encryption app.
2. Add an external storage and make it available to group Group1. (storage type: Local)
3. With userA (in Group1), upload some file to the ext storage, and it gets encrypted.
4. With admin, delete the external share from Admin page ( note, the UI does not give any warnings on consequences, it's deleted with just one click).
5. With admin, add the external storage back again, with same parameters as before.
6. UserA though still see the ext storage and the file, but is unable to decrypt it anymore.

Expected behaviour
Tell us what should happen
7. UserA should be able to encrypt it again, because nothing had been changed, only detached and attached the external storage.

Actual behaviour
Tell us what happens instead
8. UserA is unable to decrypt the file.
Server configuration
Operating system: CentOS7
Web server: apache httpd
Database: maria
PHP version:
ownCloud version (see ownCloud admin page): 9.1.2(stable)
Updated from an older ownCloud or fresh install: fresh install
Special configuration (external storage, external authentication, reverse proxy, server-side-encryption):

ownCloud log (data/owncloud.log)

Please paste possible errors in the following code block, see https://central.owncloud.org/t/how-to-find-webserver-or-oc-logfile-enable-php-logfile/808 for more info

Integrity status for oC9+

Login as admin user into your ownCloud and access
http://example.com/index.php/settings/integrity/failed
No errors have been found.

Has anyone every experience such problem or help to do a test see if it's reproducible on your side?