If the contents are not sticking as expected then it is because the column is not equal heights. Check in the browser console log for a message saying Cannot Stick : Coolumns are equal height.

Note: Some columns including Foundation 1 removes Equalize height when the top position of any column is different
Hence Sticky Grummage will not stick on stacked columns. Non-bottoming content will always float. For this reason it is advised to hide it for smaller screens.
Please ensure that you have proven that the column has an Equlalized Height in the Browser Inspector before contacting support.