No_intial_PS_candidites (sentinel-1)

Can anyone help me, I deal with snap2stamps to create timeseries analysis of a small sub-island in Mediterranean sea along north coast of egypt.
I finished all preprocessing steps before (StaMPS) matlab step.

  1. All interferograms were checked and correctly formed, and I double-checked the export step to ensure that four directories (dem, diff0, geo, and rslc) were properly created.
    So, the problem is when I applied the first step in MATLAB (Stamps (1,1) ) and make (ps_plot (‘w’, 5, 0, 0, 1)) to visualize the initial PS candidates, I didn’t find ps candidates in my study area!!!
    How can I solve this problem?
    1- I try different numbers of Patches like ( 1 patches, 2 2 patches, 4 4 patches, 2 1 patches ) but it the same problem!!!
    2- I used different version of snap (snap 6, snap 7, snap 8). still the same problem !!!