Take a look at the following strict guide - something might catch your eye:
‘Sign In to Outlook.com website is not being remembered - #2 by 289wk’
Direct access to BB Settings > Site details for Google eco-system. For each of the following, if JavaScript is already set to Allow, then scroll to the top and look for the Reset permissions button ← click that.
AFTER you have done that for the following list, then Exit / Quit BB. Start BB, and return to the Site details, setting JavaScript for each of the following to Allow:
brave://settings/content/siteDetails?site=https%3A%2F%2Fyoutube.combrave://settings/content/siteDetails?site=https%3A%2F%2Fgmail.combrave://settings/content/siteDetails?site=https%3A%2F%2Fgoogle.combrave://settings/content/siteDetails?site=https%3A%2F%2Fgooglevideo.combrave://settings/content/siteDetails?site=https%3A%2F%2Fgstatic.combrave://settings/content/siteDetails?site=https%3A%2F%2Fgoogleapis.combrave://settings/content/siteDetails?site=https%3A%2F%2Fwww.google.combrave://settings/content/siteDetails?site=https%3A%2F%2Fytimg.com
Notice, all of those have a fixed portion:
brave://settings/content/siteDetails?site=https%3A%2F%2F
followed by a domain name or host name.
When finished, Exit / Quit Brave Browser; then Start BB and test.