NC Tasks flattens subtasks after they have been moved beteween calendars by Tasks.org

Steps to reproduce

1. Have a task with subtask
2. Use Tasks.org to move it to a different calendar and note the modification timestamp
3. Cause a manual sync in Tasks.org and see that it's still a subtask; unmodified (modified timestamp unchanged)
4. Wait a minute and open/refresh NC Tasks

Expected behavior

NC tasks should not touch the subtask structure.

In fact, it should not touch any task data whatsoever unless the user explicitly asked for the specific modification to be done and merely refreshing the page should not imply any modification to be done.

Actual behaviour

The task has been modified after the NC Tasks refresh and the subtask is now at the top-level.

If you then sync Tasks.org again, it too has the subtask at the top level now, so it's not a data representation issue; NC tasks actually modified the task (modification timestamp changed) and that caused it to no longer be a subtask.

Tasks app version

0.16.1

CalDAV-clients used

DAVx5

Browser

No response

Client operating system

No response

Server operating system

No response

Web server

None

Database engine version

None

PHP engine version

None

Nextcloud version

31

Updated from an older installed version or fresh install

None

List of activated apps

Nextcloud configuration

Web server error log

Log file

Browser log

Additional info

No response

Reproduce the issue using the listed Tasks.org, DAVx5, Nextcloud 31, and NC Tasks 0.16.1 setup, following the refresh and sync steps. Trace what changes the task modification timestamp and subtask relationship during an NC Tasks refresh; done means refreshing leaves task data and the subtask structure unchanged unless the user explicitly edits it.