Does it happen the same in Chrome? If yes, you need to contact the extension developer.
If it is only in Brave, try to switch Shields off. Maybe the extension is trying to connect to certain resources in the background that are blocked.
We’re also facing this issue. And in our case because we deploy the extension via MDM, it’s not even possible for users to try to repair or remove the extension. Even if we remove the requirement for the extension, it appears to persist in some people’s instances of Brave.