https://musicbrainz.org/user/Zas/tag/%E2%80%ACheavy%20psych
https://musicbrainz.org/user/Zas/tag/heavy%20psych
 
For example, https://musicbrainz.org/artist/bf7e4b62-e71f-4ce8-82a3-3097a230bee4 apparently contains "heavy psych" in both genres and tags (though that's not really the case, as those differs)
 
First one prolly comes from copy'n'paste, it contains  POP DIRECTIONAL FORMATTING UTF8 character (https://unicode-table.com/en/202C/).
 
In this context, such character doesn't make much sense, but it was copied over, and lead to a duplicated tag (visually).

While UTF-8 characters should remain totally legit of course, such situation isn't desirable imho. May be we could improve filtering of such, dunno.