Hover tooltip doesn't show total items

[carload122]

1. set NoScript Preset customization to Default with only "frame" and "noscript" permissions
2. go to a page with scripts, such as https://windscribe.com/
3. set "...windscribe.com" to TRUSTED, and let the page reload
4. hover over the NoScript icon

The icon shows "Blocked 0 of 0 items."

5. switch tabs using the same Firefox window, and switch back to the original tab
6. hover over the NoScript icon

The tooltip now shows

Blocked 0 of 4 items.
<script>: 0/3
<font>: 0/1

on latest Firefox