Best practice would suggest you notify your uses of issues with financial transactions via your splash screen that uses see every time they open a new tab.
If you can show me stats on how many trackers Brave has blocked, you can show a reassuring sign to every user that describes why you haven paid out yet, updates to the problems, and apologies for not fulfilling your contract to your user base.
Statistically, every person that complains is worth many thousands that don’t bother.
I stopped recommending Brave, because I decided you were a scammyscamscamscammer (to get past your absurd censorship). Even now, I suspect we will see a notice of receivership or something soon.
It’s just not the way real companies behave.
Here are some nice places you might use for public announcements…
Or you could change the background image. That would be easiest. Change it to a public announce or update to the issue if the background isn’t being used as an ad. That way everyone would see it.