Some magnets are using ; instead of & between trackers, e.g.:
...&dn=title&tr=udp%3A%2F%2Ftracker.opentrackr.org%3A1337%2Fannounce;tr=udp%3A%2F%2Ftracker.coppersurfer.tk%3A6969%2Fannounce;tr=udp%3A%2F%2Ftracker.leechers-paradise.org%3A6969%2Fannounce;tr=...
This results in them being added to the torrent client as a single, long, broken tracker.