Values of “NumNeighbors” and “Distance” are changing because of setting property ‘OptimizeHyperparameters' to ‘auto’ which will try to optimize the “distance” and “NumNeighbours” parameters.
Refer to the following link for more information about ‘OptimizeHyperparameters'
To pick best estimate, bayesian optimization acquisition function 'expected-improvement-plus' is used. It calculates best estimated feasible point using ‘bestpoint’ function.
For more information about ‘bestpoint’ refer the link
Hope this helps!
