First of all, I wouldn’t worry about malware. This does not sound like that. Second, I checked my browser and did an nsfw search in “videos” and also got a “moderate” return. However, the web tab and images tab do return the correct thing. For some strange reason, Brave search does not do nsfw video searches. Maybe someone from the team can tell us why?
If Brave search does not fulfill your needs correctly, it is trivial to just change the search engine used. It has nothing to do with the browser.
Edit: I just re-read your post and it looks like you are using Edge browser with Brave search? Edge is one of the worst browsers you can use by the way.