Question about multi-master stack splitting in s1tbx

Hi all,

I use one common master image to create a single-master stack. As it is shown in the following image:

Then, I would like to split this stack into several different substacks with their own master images. I found the “Split stack into multi masters” operation in “Coregistration-> Stack tools”.

After this processing, I got the following results:

It seems that the original stack is splitted into substacks with sequential image pairs, and the first one is the master.

But when I use “interferogram” tool to create the interferogram for each one. The output is:
It says

[slvProductName] is null!

Does anyone how how to formulate interferograms after multi-master splitting of one stack?

Thank you!