The Page automatically detects the ListView as its flickable and adapts the listview's contents margins accordingly. The button position is not affected and stays hidden behind the header.
Setting page.flickable: null and removing the anchors of the page should fix it for you.
However, the automatic behavior is not correct in this case, and I will try to fix it, and I will update the documentation of page.flickable.
The Page automatically detects the ListView as its flickable and adapts the listview's contents margins accordingly. The button position is not affected and stays hidden behind the header.
Setting page.flickable: null and removing the anchors of the page should fix it for you.
However, the automatic behavior is not correct in this case, and I will try to fix it, and I will update the documentation of page.flickable.