update loop

[justjakka]

after deleting the database and reimporting previously imported files, running update several times does nothing:

Mothtek - E-LIP 01 - Smash It
  genre: Hardcore -> Frenchcore
Mothtek - E-LIP 02 - Inplantation
  genre: Hardcore -> Dubcore
Sana Logic & DJ 乾紗凪 - X-CLA 01 - MI・SE・TE
  genre: Hardtek -> Hardcore
SANY-ON - E-LIP 02 - Emanation
  genre: Hardcore -> Dubcore
SANY-ON - E-LIP 02 - Blunder
  genre: Hardcore -> Hardtek
DJ SHARPNEL - E-LIP 01 - Generative Disco vol.1
  genre: Hardcore -> UK Hardcore
Supire - E-LIP 02 - Altair
  genre: Hardcore -> Hardtek
Titancube - E-LIP 02 - plot-twist
  genre: Hardcore -> Dubcore
uet - E-LIP 02 - 邂逅Alien Dancin'
  genre: Hardcore -> Hardtek
yusi. - E-LIP 02 - Caustic Waves
  genre: Hardcore -> Dubcore
Zekk - E-LIP 02 - Teardown

while write wants to overwrite existing genre tags to a genre tag which came from a random track from the album

how can i fix this?

[justjakka]

seems like this behaviour appears after importing files and then running mbsync (with genre option no)
running beet mod on files removes the loop, but after running update a couple of times the changes resurface