Paint Brush not showing up on Stage

I had been drawing on the stage with the paintbrush tool. It was showing up on the stage as well as the icons in the timeline and the layers to the right. Now I am doing the same, and the marks I make don’t show on the stage. They are showing up on the timeline icons for that panel and in the layers, so I believe the paintbrush is working, but for some reason, nothing shows up on the stage. What is going on here?