Using GKP

I am doing some keyword research, but seem to run into an issue with data not matching on keyword planner. I know this is shitty software but i can't afford Ahrefs atm.

10K – 100K monthly searches, High (competition)—$1.48 $4.32 100 (competition indexed value)

However, when i use the 'get search volume and forecasts feature', the total impressions from a max ad spend is 380? How can 10k-100k become 380?

Any help here is greatly appreciated, thank you.