PictureThumbnailURL is null in the web part but return by the Search API

[londify]

Version used
Ex: 4.11.1

Describe the bug
Trying to get the image preview to work. Using PictureThumbnailURL in the PreviewImageUrl slot. However when I go to debug mode the value for is always NULL. When I search for the document using the REST API, I can see that there is a value for PictureThumbnailURL.

To Reproduce
Detailed steps to reproduce the behavior:

Add PictureThumbnailURL to selected properties in search results web part
change to debug mode
Notice that the value for the property is null

Search for the file via the rest API in a browser.
Property PictureThumbnailURL has a value
Expected behavior
The PictureThumbnailURL property should render a value in the search results web part

Screenshots
PNP Search Results - Thumbnail NULL
PNP Search Results - Thumbnail From REST API

**Desktop **

Browser: Microsoft edge
Additional context
Had a search call with Microsoft as the value returned via the search API for PictureThumbnailURL would give an access denied error when putting it in the browser. That is now rectified after doing a full crawl on the affected libraries.

[kasperbolarsen]

using isDocument:1 xlsx as query I get a value in PictureThumbnailURL , both in the debug layout and in the Network tab in Developer tools.

Can you verify if the issue still exists, and provide a sample that shows the issue

[ERTVZ]

I had the same issue 2 months ago. I used {{item.PictureThumbnailURL}} instead of {{slot item @root.slots.PreviewImageUrl}} to make it work. No idea if the issue still exists as my "solution" did the trick for me.