I noticed that infinite scroll works fine on mobile, but not on desktop/Nest Hub sizes. After looking into it, it seems the .load-more-sentinel div has zero height, so the IntersectionObserver was never triggered.
A very simple fix I did is to give the sentinel a small height (e.g., 1px).
.load-more-sentinel {
height: 1px;
}
I tested this on Meta as well and it seems to fix the issue.