Coregistration: not overlapping areas

I’m trying to coregister two images relevant to
i have executed all the step described in the tutorial HAZA03_Land-Subsidence_Mexico-city.pdf as reference considering VV band IW3 burst and 1 to 4 burst.
I’m not sure the results of the coregistration is ok.
Here attached the picture result of coregistration where i think to see not overlapping areas.
Furthermore attached the final result.
Thank you for your suggstions.