I would try a less diluted mix. And I found that either brushing entire side of home with a soft brush and/or decent white tip wand-ing the whole side may be necessary.
The after photo you have don’t look horrible…If they had brown fence stain on the side of that home it’d stick out like a sore thumb. But now you have to look for it to notice it.
-What expectations did you set with homeowner?
-Did you promise to make it look like brand new siding?
-Does it currently look better than what it was before you touched it? (as I don’t remember seeing a before photo with the original stain on it).
-Is the homeowner happy with results or are you striving for perfection?
Edit - you don’t need to respond to those questions. That’s just what’s rolling through my mind as I’m looking over this.
