Pen Tool Issues

I've been having the same issue with the pen tool for about a week now. Photoshop is updated and I haven't changed any settings. I create a new layer, draw a shape with the pen tool and when I go to fill the shape with colour it does not fill. If I go to other layers where I've previosuly created shapes and filled them, I'll draw a new shape and try to fill with colour but the shapes I've previously made on that layer change colour instead. In addition, the foreground colour picker now doesn't work when I use the eyedropper. Any help would be great.