Standard View Filters on Subfolders in Sharepoint Library won't work

Hey there,

i wanna activate a View Filter as Standard for a Subfolder in a Library, but it won't work. Is this a bug or is this a normal behavior?

I tried already this MS Docu here; https://learn.microsoft.com/de-de/sharepoint/troubleshoot/lists-and-libraries/per-location-view-settings-fail-working

At the End i can't chose a Standard View for a Subfolder.

If i set Test 2 as Standard, it will be shown by all Folders, not just by this Folder