There could be a few reasons to why you are unable to move the slider:
1. When there is no click data, it is not necessary to adjust the slider;
2. When all hot spots have a similar number of clicks, it is not necessary to adjust the slider (Overlay Click Heatmap);
3. When all areas of the page have the same idle time, it is not necessary to adjust the slider (Overlay Attention Heatmap);
Mouse over the top of the screen, just below the address bar and the toolbar should appear. In the toolbar,
Click ‘Packup’ to hide the toolbar
To show the toolbar click on the area marked in red at the top right end side of the screen as shown in the screenshot below.
Click ‘Refresh’ in the toolbar.
I’ve changed the window size of my browser, and the Heatmap is no longer accurate!
After you’ve resized the webpage, click ‘Refresh’ in the toolbar to adjust Overlay Heatmap for that page size.