The scenario I was thinking of, and probably not explaining very well, is:
You connect to your VPN service.
You open a browser and visit a website.
While you’re on that website, you (or the client) disconnect from one server, then connect to another server.
If your VPN service has protection against data exposure during a lost connection, no problem. But you may have to restart the browser.
If your VPN service does not have protection against data exposure during a lost connection, then I would think that your real IP is exposed momentarily.
Add in switching between providers while the browser is open, even more so.
I’m not familiar with Brave’s protections.