You can see and change the most commonly changed options for each block using the icons in the block list: 
Click the Autoscale icon 
 to toggle between using autoscale for a plot and using the block's custom set range.  This can also be accomplished be checking and unchecking Groups | Autoscale All Blocks, or by selecting Block | Autoscale Mode.  The icon will have a white background if the plot is using autoscale, or a gray background if the plot is using a set range.