Certain lands (Command Tower and basic lands at a minimum) are counting as 0 casting cost cards in the Mana Curve data at the top of each deck list. This started with the Throne of Eldraine update but I didn't notice it until now.

I'm guessing this is probably related to some of the issues with Throne of Eldraine Brawl deck data.

yes it happened with eldrain
my guess is they used to have a NULL CMC, but with the set it was put in with a 0 CMC