We are currently doing work on our end, this should be resolved soon:
Same issue - only tried using the Brave browser on Debian 10.
Sorry - I don’t know how to insert a “screen shot”…
(update: Brave Search works for me now)
We have resolved the issue and reset the 24hr lock for users who were locked out due to too many attempts. You should now be able to authenticate and search.
Now logged in and it looks to be working 
Thanks for the swift response.
I have access to the beta, but when I try to use Brave Search in a private window, I get the error “It looks like your beta program credentials are missing or expired” Enter the email … etc.
I can see why it wouldn’t be recognized in private mode, but is there a way around it rather than submit my email every time? Not sure how long it’ll be before it rolls out to everyone.
@752bfc1c933407ba6a19,
Unfortunately no – that behavior is to be expected for the same reason you’re not logged into other accounts when you open a Private window.
Apologies for the inconvenience.
I got a link to the beta for the search, but am getting a blank screen, similar to pictures posted here (without the confirming your access status message).