I'm glad I decided to do a tiny track in another location, with decent grass on the start and see what the difference 'might' be...still can't be certain what the problem was the other location.
Now this track was also barely aged, but the idea was to motivate him at the start and continue on the first leg totally ON the track and enthused. So that worked well.
The battery went dead on the camera after this picture above. The short track went across a wide driveway, into grass with a turn, cloth article, and a man and his son walking across it in front and also on the next leg over the driveway and into the grass. No issue with them or their tracks. Blast just took a good look at them and dismissed them. He did great on the last leg under and through large pines, sparse veg. covered with pine needles and his ball at the end. Leaving him with this little excellent track was a good plan.