Okay those Boxset tags are added by SongKong if you have the Add RoonAlbumtag to albums identified as box sets option enabled, this is disabled by default but enabled if using the Roon Profile
This option was added because of a discussion with Roon customers using the Roon album tag as a workaround for having problem with boxsets in roon,sounds like need to revisit this.
You can remove these tags from your original files by using the Metagrater task, and adding the Roon Album Tag to the list.
