the infos you are providing are too few to understand your case.
First of all, in the PSC selection there is also a sparsing operation applied (points are made sparser according to the DS and DL values). You should check it.
Secondly, I am wondering whether your overwrote the coherence file.
To understand better, I suggest you load the temporal coherence using the “load mask” function in “site processing” (threshold =0).
Then you can also plot the values or check the histogram to see what you physically have in the file.