p-value computed by the Kolmogorov-Smirnov test is known to be biased if the parameters of the theoretical model are not fixed but, instead, they are estimated from the observed data. In particular, the computed p-value is overestimated, hence we run the risk of accepting the fitting hypothesis also when the data does not really come from the theoretical distribution.
I do not understand what (the computed p-value is overestimated) mean, does it mean that the computed p-value is larger than it should be than one that we would have its table