You’re welcome! Just wanted to let you know that enabling Fanboy Annoyances List is enough to hide this particular cookie window, but uBlock Annoyances List is another great filter list, using both filter lists is highly recommended if you would like to get rid of as many annoyances as possible.
I found out AdGuard Annoyances hides the cookie window on Facebook, but that makes the page unresponsive. You can give it a look on desktop, but you’ll have to install either uBlock Origin or Adguard because subscribing to custom filter lists is a work in progress in Brave.
You might have to use a custom filter to hide that cookie window, but it’s not guaranteed that Facebook will function normally. Some websites, for example Google and YouTube, don’t work normally when users bypass the cookies consent. I would say Facebook is also such a website since Adguard Annoyances broke website’s functionality upon hiding the cookies consent window.