easytag: genres 80s/90s replaced with 'folk'/'avantgarde'

Easytag doesn’t seem to handle tags with numbers very well. If my genre is 80’s or 80s, it displays folk. And for 90’s or 90s it displays ‘avantgarde’. Amarok sees the correct tag 80’s and 90’s. Even when I change it with easytag, it goes back to folk and avant garde when easytag reloads. As a workaround I will use ‘eighties’ and ‘nineties’ but I wonder what the problem is…

PS I use latest id3v2 so that’s not it.