Directory deleted after deactivation of sync

Nextcloud version Nextcloud Desktop Client Version 3.5.1 (Ubuntu). ubuntu-5.14.0-1042-oem
Operating system and version Ubuntu 20.04.4 LTS
Nextcloud version on server 23.0.6

my nextcloud is set up in a way that it has a parent/root directory in my home to sync (let’s call it ncsync). Inside this directory, I have several directories that I selected or deselected for sync. I’m using the GUI of Nextcloud client on Ubuntu.
Here is what happened:

  1. I deactivated the whole sync some months ago
  2. Since then I worked on my files in subdirectories of ncsync
  3. Yesterday I activated the sync again
  4. Then I saw that one of the subdirectories was something like 200 GB that had to be synced so I removed it from being synced
  5. Now instead of leaving this directory alone, Nextcloud deleted it from my local machine! What I’m left with is the version from several months ago on the server.

Frankly, I’m quite desperate. Firstly, because it is data that I need very urgently back but I see no option to restore it. Secondly, I think: WTF!?! How can this be the default option in Nextcloud? Do you want to deactivate the sync? Ok, I will delete the files for you. Nevermind.

I would appreciate it a lot if someone has an idea.


It is a known bug:

I will try to cheer myself up with the fact that it is a bug that was first reported 2019 while repeating the work of 5 months.

Whatever Nextcloud client is doing when deleting the files, it does it properly. Neither testdisc nor extundelete can be used to restore the data.

It’s a bit surprising, because normally they handle such issue with possible data loss with high priority.