I have even weirder behavior. The list is 43 items. Sometimes I see all 43, without load more button. I see them all. Sometimes, same page, same “session”, I see only 10. This is the page size of the listview. I can't see beyond the 10. It doesn't load automatically. Then seconds later, when I go back to the page, it's 43 again. And vice versa.
The modeler will show this when modelling. However on the native platform we are not using it. The loading is done automatically for you when list is scrolled to the bottom. this pattern is way more mobile friendly.
I just opened a PR in docs to explain this, https://github.com/mendix/docs/pull/2212/files