I am currently using the Redmine Jumpbox and have been fine until switching it over to https. When submitting forms once I switched it would send the form to http instead of https. I did some brief research on the redmine website and found it is a known issue. You need to add the following line to the ssl website setup:

RequestHeader set X_FORWARDED_PROTO 'https'

The article I referenced is here: http://www.redmine.org/issues/show/1145

after loggin into the console and adding this line to the default-ssl.auto file I am now running correctly in https.