Microsoft Lists - Can't Save To "My Lists"

So I'm a Global Admin. I have 2 tenants. On one I have an E5 license on the other I have an E3. I don't know if this makes a difference or not but that's the biggest diff I can see between the 2. 

On the E3 tenant I am able to access the Microsoft Lists app, create a new list from an existing list, and save that new list to "MY LISTS" in the save to drop-down.

On the E5 tenant the save to choices DO NOT include "MY LISTS"

What am I doing wrong? Why can I create a list from an existing list and choose to save it to "My Lists" on 1 tenant but not the other?