When using the gateway in directory listing mode, if you have a double slash in the path, the request won't find the folder or files.

I suggest removing extra slashes from the path using a rewrite, a map in the config or from JavaScript.

Example:
https://example.com/pathFoo//file.txt would become https://example.com/pathFoo/file.txt
https://example.com/pathFoo//subpathFoo/// would become https://example.com/pathFoo/subpathFoo/