File Alias only works when matches exact File Path directory

I am not sure if this would be related to this module or only to the File Aliases module. But I will place the issue I'm encountering here as well in case it's related to this module.

I have a case where I would like for the file path stored location inside my files directory [sites/default/files] to be different then the url alias the user will see.

Expected behavior I would have liked was for the URL the users see when the file is served to them sitedomain.com/category/filename.pdf and the actual file is stored at sitedomain.com/sites/default/files/pdf/category/filename.pdf
However when setting these in the file field path settings I'm getting the drupal error "The requested page .. could not be found."

If I set the file path and file alias settings to both include the pdf/ in the beginning of the path like the following then the file gets served as expected.
File Path: pdf/[node:field-category:url:relative]
File Alias: pdf/[node:field-category:url:relative]/[file:ffp-name-only-original].[file:ffp-extension-original]
Then the file gets served as expected at sitedomain.com/pdf/category/filename.pdf

See this issue for step by step instructions on how to reproduce bug.

Any feedback would be greatly appreciated!