Hi, i have kind of same issue.
When i first click on a download link like torrent magnet link, it works … but when i second click on another magnet link it lets me on a blank page.
That happends on yggtorrent.si with brave.protection ON and OFF.
OS ubuntu_mate 20.04
brave Version 1.19.86 Chromium: 88.0.4324.96 (Build officiel) (64 bits)