This may sound like a strange question, but have you selected the Ward of Dawn in your super options for your Void subclass? It'll be dark if you have it selected (Yes, I know, dark normally means deactivated, but it turns dark when you select it because the other is now the only option to switch to, thus the other is lit up). You'll know you have Ward of Dawn selected as hovering over the large icon will say Ward of Dawn instead of Sentinel Shield. The new Void version doesn't let you do the Shield or use the Ward on the fly by pressing or holding like you could before the change to Void subclasses; you have to select one super or the other super.