Ah I think I got why. I downloaded the .tsv of hematopoietic and lymphoid system neoplasm (umbrella disease) from the exact same disease association page in March 2022 (two months ago), and the .tsv of T-cell non-Hodgkin lymphoma yesterday. It seems there has been a version update between this two time points, and the number of targets of the umbrella disease decreased from 10679 to 10350.
Sorry for bothering you… I just can’t download the large table of the umbrella disease now (because of an issue), but weirdly, I can download the T-cell non-Hodgkin lymphoma one (perhaps because it’s small), so I wanted to use these two datasets together. But it looks like there are indeed some inconsistencies (update) between the two versions.