new annotation button doesn't work on scroll

[jLouzado]

• after annotations are loaded, scroll down a little bit

• even though the buttons are visible and the tooltips are working, clicking on the button does not have the desired effect
  • it looks as if the click is actually registered on the annotation. and the button is hidden underneath
• to properly get things working you need to scroll back to the top and click

[jLouzado]

only on Firefox (62), works fine on Chrome (66)