Responsive Grid View appearing in single column
You need to apply some css rules to the output. Basically, assuming each div of the grid has a views-content class, give that class a float:left and some margin. Or if you use a responsive theme already, set the correct classes to the output in Views UI...

As per the Views Responsive Grid:


  In order for the columns to work you'll need to specify the class name
  of your columns. For example, if your theme utilizes a grid, like
  Twitter Bootstrap does, you would specify "span3" as the column
  class(making sure to use the correct span size). This will make sure
  your column adhere to the grid in your Bootstrap based theme.