Use with reverse proxy

I’m having trouble with the plugin using the wrong URL for the redirects.
I am using a reverse proxy which could be the problem…

Here’s an exmaple…
Full URL: http://www.bmc.com/blogs/transforming-inside-bottom-top/

Short version: http://bmc.co/1r6qaBr (redirects to http://s7280.p20.sites.pressdns.com/transforming-inside-bottom-top/)

https://ww.wp.xz.cn/plugins/wp-bitly/