Exclude OneDrive folder from SharePoint Online search

Hello

I have tried the following to exclude from Search a folder with the name "TEST" in my OneDrive root, as specific User have access to that folder by using a flow only they can see the created documents in search results. I need to hide that documents and I am deleting that documents after an Email is send from that flow, but its essential that nobody can find the documents over the search in SharePoint.

So I have excludes the path to the folder by using the following steps:

(1) Went to site settings of my OneDrive

(2) Clicked on "Result Sources" and was setting up a "New Result Source"

(3) Created the following query with the QUERY BUILDER:

path:"https://xxxxxxxxxxxx-my.sharepoint.com/personal/UserName_company_de/Documents/TEST" -ContentTypeId:0x0120*

(4) Test was showing NOT that folder

(5) Checked if the folder was showing up without CONTAINS NOT by using the same query without "-"

"ContentTypeId:0x0120*" and it was working, folder was showing up as only result.

(6) Set that "Result Source" as DEFAULT.

After that I tried to search in OneDrive, the folder still exist in the search results.

I tried the same from the Home Page in SharePoint Search field, same result, I can see the folder...

If somebody knows another way please let me know ;)

Thanks in advance.
Kind regards

Michael