Site Home Page won't Resolve without Trailing Slash

We have been instructed to use a folder type system for a number of sites (as contexts in one MODX install). For example:

Main Site: http://www.whatever.com
Related Site: http://www.whatever.com/ca/fr (French Canadian Version)
Related Site: http://www.whatever.com/newyork/grimrock (A related site in the New York Region)

We are using XRouting (Github here) for the context routing so for the sub sites we would use the following settings:

French Canadian Site
http_host: whatever.com
base_url: /ca/fr/

New York Site
http_host: whatever.com
base_url: /newyork/grimrock/

The issue is if a user visits: http://www.whatever.com/newyork/grimrock

We get a 503 Error.

If a user visits: http://www.whatever.com/newyork/grimrock/

Note, with the trailing slash. It resolves successfully.

If we change the base_url to: /newyork/grimrock

Note, without the trailing slash. Then this: http://www.whatever.com/newyork/grimrock

Resolves successfully, but then any other pages do not, such as: http://www.whatever.com/newyork/grimrock/about.html

Yet when we restore the base_url to: /newyork/grimrock/ and go click the About link, even though the URL is exactly the same (i.e. http://www.whatever.com/newyork/grimrock/about.html) it resolves successfully.

So the challenge we have is how do we automatically add the trailing slash to just the home page URL?