[Bug]: Asset thumbnail URLs in Studio missing parent folder segment when assets are not in root

[moinferdi]

Studio API version

v0.13.20

Steps to reproduce

1. Create an asset folder structure with at least one level of nesting, e.g. /client-a/project-b/images/
2. Upload images into a subfolder, e.g. asset ID 89 at path /client-a/project-b/images/category/subcategory/
3. Open Pimcore Studio and navigate to the asset tree
4. Observe that thumbnails are not rendered – only the placeholder icon is shown

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The asset tree is structured as follows (confirmed via DB):

id=1    path=/              filename=(root)    type=folder
id=121  path=/              filename=client-a  type=folder  ← top-level folder
id=17   path=/client-a/     filename=project-b type=folder
id=89   path=/client-a/project-b/images/...   type=image

The top-level folder client-a (id=121, parentId=1) appears to be skipped when Studio builds the thumbnail URL. The generated URL starts at project-b (id=17) instead of client-a/project-b.

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The browser's network tab confirms the following for each affected asset:

• Studio sends a GET request for the thumbnail URL with the truncated path
• The server responds with 302
• The redirect target is /bundles/pimcoreadmin/img/filetype-not-supported.svg

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• The pimcore-system-treepreview thumbnail configuration exists and is generated correctly on disk
• The classic admin UI (/admin) resolves and displays all thumbnails without issue
• No errors appear in var/log/ related to thumbnail generation – the thumbnails are simply requested at the wrong URL by Studio
• Installation is without Docker, running directly on Ubuntu with Nginx

Actual Behavior

Studio requests the thumbnail at:

/project-b/images/category/subcategory/89/image-thumb__89__pimcore-system-treepreview/filename.jpg

The first path segment (/client-a/) is missing. The request returns a 302 redirect to filetype-not-supported.svg because the file cannot be found at the incorrect path.

The thumbnail does exist on disk at the correct path and is rendered correctly in the classic admin UI.

Expected Behavior

Studio requests the thumbnail at:

/client-a/project-b/images/category/subcategory/89/image-thumb__89__pimcore-system-treepreview/filename.jpg

Which resolves to the physical file at:

public/var/tmp/thumbnails/client-a/project-b/images/category/subcategory/89/image-thumb__89__pimcore-system-treepreview/filename.jpg