When you enable sidebar the content is narrowed and that’s why footer section is narrowed too as it’s related to the page container.
The solution can be using the code I provided you in the previous post.
I’ve created a Test Static Block. Then set it like sidebar and it’s working fine.
See screenshot: http://prntscr.com/6ae5r3
In your Static Block you forget to add Row element. Please recreate your block like to my Test block.