One to Many relationship: Missing subpanel

I am particularly interested in this default relationship in Cases module:

According to the description for One to Many, there should be a Notes subpanel shown in Cases module.

However, In Cases module, I can only see the subpanels of those with Many to Many relationships.

Why is that so?

Running on version 8.8.1

Hello,

Notes (like calls, meetings and tasks) are “special activity” modules.
You’ll find the future ones in “Activities” and the past ones in “History”.
Notes are part of the History subpanel:

I’ve got some more details about the activity modules in one playlist:

@BastianHammer

I see. Thank you!