I believe I'm experiencing the same issue as Vizualinx.
You can see his popover div contains the attribute popover auto.
Based on the NordCraft video, this should make the popover disappear which isn't the case here.
The popover remains and the trigger correctly places it above all other elements.
In my case, since the popover remains, it pushes down all elements and isn't the behavior shown in the NordCraft videos.
Update: After reading the documentation that MVvdV graciously posted, the popover is hidden via display: none. My div was set to flex which explains why it wasn't hidden with popover auto. 😅