[Help with Adding Bokeh]

I followed the video tutorial on 'Adding Bokeh' accurately as far as I know.  I've added the maximum blurring effect, duplicated the pixel layer, and added another layer as instructed (below the pixel layer).  

 

The problem is when I use the paint brush to bring a specific portion of the photo back into focus, nothing happens.  I paint over the area but it stays as is, completely blurred.  It looks fairly straight forward in the video when then horses and zebra in the examples are painted and sharpened, but it's not working for me.  

 

Thank you.  Overall, I'm really happy with Affinity.  It's an amazing program.  This is the first problem I've encountered.