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.
Usually I'd select the foreground colour first. Use the pen tool to create a shape. Once the shape lines met up with each other I'd right click and choose 'Fill Path' and make sure it was fillignt he path with the foreground colour. See the image attached where I give an example of setting foreground colour, using pen tool to create a shape and then filling with colour. But then I press ok it doesn't fill. Thank you.