[Bug]: Folders navigation has expand button when there is no children

[DorraJaouad]

⚠️ This issue respects the following points: ⚠️

• This is a bug, not a question or a configuration/webserver/proxy issue.
• This issue is not already reported on Github OR Nextcloud Community Forum (I've searched it).
• Nextcloud Server is up to date. See Maintenance and Release Schedule for supported versions.
• I agree to follow Nextcloud's Code of Conduct.

Bug description

In the left side bar, folders tree show expand/collapse button to subfolders that don't have children. Sometimes, it stays shown until you press the item but usually it's momentary.

Steps to reproduce

1. Have a folder tree
2. Create a subfolder with no child
3. Close the tree, reload and open the tree until the childless folder.

Recording.2025-02-20.175659.mp4

Expected behavior

Have no collapse button

Nextcloud Server version

30

Operating system

None

PHP engine version

None

Web server

None

Database engine version

None

[skjnldsv]

I think preloading with depth=2 would solve this.
As anything deeper than 2 levels would be hidden within its parent folder. So preloading the parent would avoid not knowing the state of the sub-children