Firefox 80 return from fullscreen hides buttons at bottom of screen

[caniwi]

Describe the bug
User running bigbluebutton on Firefox80. User escapes from fullscreen mode and the buttons at the bottom of the window are not visible. Resizing the window makes them re-appear. This behaviour does not manifest itself with other backends after going fullscreen.

To Reproduce
Steps to reproduce the behavior:

1. Enter a bbb session.
2. Make a component (presentation, camera etc.) of the session fullscreen mode.
3. Escape from fullscreen mode.
4. Buttons along the bottom are hidden by the reduced component.
5. Resize the window changes the component and the buttons are revealed again.

Expected behavior
The component, when reduced from fullscreen mode, should reveal the action buttons.

Actual behavior
A clear and concise description of what you expected to happen.

Screenshots
If applicable, add screenshots to help explain your problem.

Desktop (please complete the following information):

• OS: Ubuntu 18.04
• Browser Firefox 80 (does not happen in Firefox 79, Chrome or Chromium)[e.g. Chrome, Safari]
• Version 80

Smartphone (please complete the following information):

Additional context
Confirmed it happens in BigBlueButton 1008 and 980. This does not happen with other apps (youtube, alfresco, lool) going to and from fullscreen mode.

[ffdixon]

Good catch!

[KDSBrowne]

There is already mention of this in #10155, It was introduced by #10144. I believe @vitormateusalmeida is working on it?

[prlanzarin]

I don't think it's related to that PR, @KDSBrowne. It happens on latest 2.2 as well, so probably something related to FF 80.

[KDSBrowne]

@prlanzarin I think your right

[KDSBrowne]

This issue seems to have been resolved in the latest version of FF 81.0 (64-bit)

[caniwi]

I agree it does seem to be resolved in FF 81.0.