Most shapes in block in Codeblocks have inputs where you can type in numbers to change their attributes. Each of these input has a minimum and maximum range limit for that input type, Length for instance.
Sometimes when you are creating your design you will run into the min or max number for each. For example, you might type 100 mm for Height on a shape and then decide to change it to 120. If you don't see a difference, it means that you have entered a number beyond the min or max limits. If 100 is the max limit, the shape will stay at a Height of 100. This can be the same for entering a low number on an inout like Sides which might have a minimum limit of 12.
So, if the Shape is not updating when you change the inputs, it likely means that you are either above or below that input's minimum or maximum limits. If this happens, the best thing to do is switch over to using the Scale block to make a shape longer or maybe switch to different shape that might allow you more control. (Tip: I really like the Cone shape because it provides the max amount of control versus the Cylinder or Polygon.)
We know that this is can be frustrating, but since the Codeblocks workspace is still a work-in-progress we haven't had the chance to create error messaging or UI help to let you know what is happening. We're working toward a solution and hope to release it in the near future.