Snooze Tabs panel wrongly remains displayed when showing the browser window in full screen

[SoftVision-CarmenFat]

[Affected versions]:

• Release 58.0.2 and up
• Snooze Tabs 1.1.0

[Affected Platforms]:

• All Windows

[Prerequisites]:

• Have a Firefox profile with the latest Snooze Tabs add-on version (https://github.com/bwinton/SnoozeTabs/releases/tag/1.1.0) loaded as a temporary add-on.

[Steps to reproduce]:

1. Open the browser with the profile from prerequisite.
2. Navigate to a website (e.g. www.wikipedia.org) and click on the "SnoozedTabs" button.
3. Press "F11" key and observe the panel.

[Expected result]:

• The panel is dismissed.

[Actual result]:

• The panel remains displayed in the same place.

[Notes]:

• On Firefox Release 58.0.2, the panel is moving up along with the browser toolbar.
• The Snooze Tabs panel will still remain displayed, but it will be blank if the browser is resized before going into full screen.
• Attached a screen recording of the issue: