Some problems with the result of Yamaguchi decomposition

Hello, everyone. I encountered some problems when doing the Yamaguchi decomposition.

Problem one:
Comparing other decomposition results, why the result of the Yamaguchi decomposition has a black margin, as follows in the figure?

Problem two:
I think the black margin is the null value, but why is it showing the dB value as -150?
The figure shows the dB value of the double bounce band equal to -150 after doing band math.

Problem three:
Can remove the null value? If can, how can I do it?

Thank you.
Looking forward to your reply.