URL: https://signup.euw.leagueoflegends.com/en/signup/redownload

Browser / Version: Firefox 70.0
Operating System: Mac OS X 10.15
Tested Another Browser: Yes

Problem type: Video or audio doesn't play
Description: The background video runs at a low frame rate compared to other browsers
Steps to Reproduce:
The background video loop is running at a very low FPS on my Macbook Pro Late 2016.

When you open this link in Safari and or Chrome you will not see this same issue.

I've also checked on Windows 10 on another PC and it's okay. Seems to be isolated to Firefox.

My Macbook Pro at the time of this is

• Plugged in, fully charged
• GPU: Radeon Pro 460 (4GB DDR5)
• CPU Skylake i7
  

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