Problem in coregistration


I am using RS2 dataset for my project. I am having following issues:

When I perform calibrate—coregister—multilooking with window size of 32 by 32 in coregistration, NaN values still exists even after unchecking no data value.

When I perform multilooking---->calibrate—>coregister, with the same window size, coregistartion is not perfect. Help related to the mentioned problem is highly appreciated.