I've simulated a testing genotype and phenotype dataset. I've used the betas in the simulated summary statistics to calculate the sign for the correlation matrix. I did not use a reference panel, after running LASSOSUM on my dataset. I got the correlation coefficient to be negative from the best.validation.result. However, it does not make sense. What could lead to the negative correlation coefficient to be less than zero? How can I simulate my genotype and phenotype such that there will be a positive correlation.