Setting the virtual list properly

I’ve been trying to set up the virtual list inside a popup but it seems it’s not working because popup still takes some good time to load. Here’s my code:

<f7-list media-list virtual-list :virtual-list-params="{ items: Schedule.Items }">
          <f7-list-item v-for="(Item, I) in Schedule.Items" :key="`Item.Id-${I}`">

The list is very simple, no search or anything after it renders. But the sheer amount of items slows down the app when the popup is opened.