Over plan limit "Resolve this" link does not work over CNAMEs (BB-7000)

I just got a message "You're over your plan limit. Committers have read-only access. Resolve This.". By clicking on "Resolve This", I get brought to a 404 page. See screenshot.

(The url that it brings me to)
http://code.markhamlin.net/account/user/plover/plans-and-billing/

Note that going to the same URL on bitbucket.org brings me to a valid page, so it's probably a bug due to my custom domain.

(Using this instead works)
https://bitbucket.org/account/user/plover/plans-and-billing/