Affected versions
Nightly 69.0a1 (2019-06-27) (64-bit)

Affected platforms
Windows 10 x64

Steps to reproduce

• Launch Firefox
• Go to any twitch stream that has extensions, such as: https://www.twitch.tv/dakotaz
• Hover over the stream to toggle the flyout

Expected result
The PiP flyout should be displayed

Actual Result
Due to the overlay of the enabled Amazon Blacksmith twitch extension, the PiP flyout can't be reached. Recording of the issue: https://streamable.com/pa2lo

Note
Disabling the extension will make the flyout to appear and work as intended. This can be reproduced with other twitch extensions too.