Websites can use JavaScript to restrict or block the ability of the browser’s Back button.
Sometimes, I have to use a website listed (in History pop-down menu) a bit further back.
And sometimes, doing that, followed by a Forward . . . gets the browser to the desired webpage that the frustrated Back button could not accomplish.
Perhaps Brave team member @fanboynz would know how to block a website JavaScript that is designed to restrict the browser’s Back button.