Crystal Maiden's Frostbite damage tick rate was changed from 0.5 to 0.7 in the Dota Plus Autumn Update. The damage used to be 50 ticking every 0.5 seconds, but now it's the total damage spread evenly and ticking every 0.7 seconds.

This also has the unfortunate side effect of making her level 25 "+1.5s Frostbite Duration" talent no longer increase the Frostbite damage. The talent used to increase the total damage from 300 to 450, now it just spreads the 300 damage evenly over the whole duration.