Colorless lands, such as Blast Zone or Fountainport, activate abilities for 1 less mana than expected. Playing from PC, Windows. This already happened in several games and there's even footage on the internet (youtube) from a content creator. Experienced this in a few matches where my opponents were able to sacrifice a token to fountainport despite having only 1 Fountainport and 1 Plains untapped. Saw balst zone getting counters on for X instead of XX. Other opponents were able to play a 4 drop, tap Fountainport and sacrifice 2 Map Tokens to buff their creatures, despite having only 5 lands on the field. That's a huge discount, makes difference between winning and losing games.