Maybe a bug.

The template elements of matrixdynamic question contain another matrixdynamic question. The panel cannot be added correctly.
The panels should be added smoothly and dynamically.
Tested page URL: https://plnkr.co/edit/phT6BWEIfUvxjzzLCTqV?p=preview
I also struggle this kind of problem. Is there any update for this question? Thanks.
@KLC215 , @Jojo109 we are working on the problem
Thanks @tsv2013
Thanks @tsv2013
Fixed. Unit test added. Fix will be available in the nearest update.
Thanks @tsv2013