Heroku rails producion enviroment removing css vendor prefixes

I am pushing my code to heroku with a production.rb enviroment file and
when I open the css file that rails has created all css vendor prefixes
have disappeared. May be sass-rails gem is doing something weird. I
don't what is happening.

My css with development.rb http://pastebin.com/wbWwgvDG

    [layout-align="center center"], [layout-align="start center"],
    [layout-align="end center"], [layout-align="space-between center"],
    [layout-align="space-around center"] {
        -webkit-align-items: center;
        -ms-flex-align: center;
        align-items: center;
    }

My css with production.rb http://pastebin.com/0Tydqem2

    [layout-align="center center"], [layout-align="start center"],
    [layout-align="end center"], [layout-align="space-between center"],
    [layout-align="space-around center"] {
        align-items: center
    }

I have written to stackoverflow, and rails IRC but I don't get any help.

What can be happening? Do you know if another compressor can work
better?Thanks!