seems to me you drive a lot of short trips on a normal day? then this is absolutely normal. the mercedes thermal system heats the battery every trip to get good performance, this alone easily eats 2kwh or more. in summer, if you drive 10km, thats roughly 2kwh, so you see the overall consumption double if you only do trips like that and let the battery cool down inbetween. long trips, different story: my eqb fully loaded in winter temps around 0 centigrade has a consumption around 2-2.1 kwh per 10km on trips >500km, total expected range just above 300km. this is with studded tyres and 70-80km/h speed, up and down over norwegian mountain passes.
looking at carsized.com for dimensions, gives ev9 a cda of approximately .79 when compared to the eqb that has similar shape and same cd. tesla y has a cda of approximately .59, so the ev9 has a approx 30% disadvantage just for aerodynamics. rolling resistance increase linearly with weight, so there the disadvantage vs y is also 30%. 100/75 is 1.33 so this adds up.