I googled the old support forums to see if anyone had issues with accordians nesting inside each other and it seems people WANT them to but it is not supported.
But! 
I am actually having an issue with them nesting. I do not want any to show inside another one but it keeps happening. They show in the customizer but when you see the front end of the page, some are inside the others.
See image.
*Note, I do have a lot of accordians! But we need them. It is all part of one set. 
Thanks!
Noelle