There is a setting for infinity scroll, it is called , Disable auto-loading next page when browsing
I did not test wich sections this is used on, but infinity scroll ist just loading new stuff by scrolling instead of displaying a next page button.
If you have a grid of unknown many items and embed this in a page, you have limited options how to do this. Displaying all at once is just not done for collections. If they are embeded they limit it to 20 and if the actual page is the collection, then 30. I presume this is to just not load all of it. But I wonder why they do not just make a scroll bar inside the embedded collection like in library view.