In the manual you have mentioned the differential expression as following:
DEs refers to ***“different expression status”***. It is the type of genes that show significant difference in the proportion of real zeros in the two groups, but do not have significant difference in the other cells.
My doubts is, what other cells (but do not have significant difference in the other cells)? Are you taking into consideration the whole data set not just group 1 and group 2 in TestData? If so then you have only 150 samples in the TestData, how do you compare with other samples? (please correct me if I understood wrong). Could you give more insights into the "other cells" part?