I have a difficulty using a playlist type interval

I currently have my programming using scheduled playlists to be programmed in the week automatically

The problem is that the interval playlist, the program to play an audio every 5 songs at random

but it does not work

I use it with a general rotation playlist and if it works

What am I doing wrong to work with the interval list?

Hi,
for those that I know, interval playlist can be used only with general rotation, not with scheduled playlist, this cannot be interrupted.
Bye