Random Sample flow, Send Email
I'm running an email campaign. Same email, same list, with a random sample like this:

The idea is to have the same email sent to the list across 5 days, leveraging each lead only going through the flow once.
However, the 1st day sent out fine, but 2nd day didn't send and it's showing 0 people set to affect in "Schedule" tab.
I looked up Marketo Docs saying it will not work in nested Smart List, so I tried on Flow. This doesn't work too? link
Any suggestion is welcomed!