This might be happening for two reasons:
- Your page does not scroll on the document element.
- Your page uses a scroll-lock to scroll the page.
These types of pages are not supported and listed on our Heatmap Limitations. For Heatmap screenshots to show in full, Hotjar needs to know how big the document is. In both of these cases, Hotjar cannot know this, so it only takes a screenshot of what your page renders on load.