formatCard spacing breaks after 4th character

[mattLummus]

Using the code:
$('#subscription_cc_num').payment('formatCardNumber');

The space in between every 4 characters stops working once you enter more than 4 characters.

I can see it after the 4th...

But once I type in a 5th it reverts.

Have tested this in Chrome, Firefox, and Safari. Running on Macbook Pro, Yosemite.
Have also tested this in a demo I found online with same results. http://jsfiddle.net/gosseti/jv8j53nb/9/

[jenanwise]

Hi @mattLummus. The spacing between each group depends on the card type. If you enter 42424, you'll see the grouping remain. 12345 isn't a known prefix so it reverts to ungrouped.

[mattLummus]

@jenanwise That makes sense however I did not see this in the documentation. Thanks for the quick response!