Shifted bam calls more number of peaks than unshifted bam

[RadPa]

I work with Drosophila data; I used to call peaks using unshifted bam, recently, I tried shifted bam. The shifted bam is calling more peaks than unshifted, for example.

Samples	Shifted	Unshifted
sam1	15295	6034
sam2	16683	20469

Would you please explain what's happening with my data