The Library Loaded (Page Top) Event is not consistently being triggered on iFrame when embedded on a parent page

Hi Adobe experts,

Good day!

I would like to ask for your insights regarding an issue I've encountered.

Intended behavior:

The Library Loaded (Page Top) Event should trigger in both the parent page and iFrame consistently

Observation:

When testing the iFrame as a standalone, the Library Loaded (Page Top) Event consistently triggers as intended

but when Embedded in the parent page, there are instances wherein only the Parent page's Library Loaded (Page Top) Event triggers

Question:

Is there any setup or suggestion that you can give me in order for the Library Loaded (Page Top) Event will consistently trigger on the iFrame when embedded on the parent page?

Thanks in advance!