We have a simple plan, with no filter, just to show:
Initiative -> Epics -> Story/Bug
I realized that in some cases not all epic children are visualized. After some research I suspect it happens when all epic children are in DONE status, I don't know why, it is counter intuitive for me, and I could not find a setting where to change it.
Here some examples:
View in Jira Advance Roadmap: The epic: IFR-369 shows no children issues:

but in the Jira timeline shows it has Jira issues:

There is a situation where it shows only pending work. For example: IFR-370:
but in the reality the epic has more issues associated:

It is not true that only shows pending work, the following epic shows the correct information: IFR-1465

and Jira timeline shows:

Thanks for any help on this matter,
David