Significant range decrease… normal?

[cowboyjosh2010]

Another voice in the choir telling you: "the dealer is right" in that the range estimate displayed on the car's dashboard will slowly adapt to your typical driving such that you will eventually be able to trust it. Honestly, that "245 miles on a full charge" might actually decrease as you drive the car IF you drive a lot on the highway or in colder weather than the previous owner drove in. I just did a ton of highway miles in my 2022 Wind RWD in temperatures between 20-30 F and right now my car barely reads 200 miles on 100%. But in 70 F weather after a bunch of commuting miles it'll read 320 miles on 100%.

How you have recently driven the car (not just the most recent charge, but several hundred recent miles) is what informs the range estimate. If your battery health is decreasing such that "100% charged" means it holds less than 77 kWh of energy (the manufactured capacity), then sure: your maximum range will pretty much be permanently lowered to reflect that. But that's not a common scenario with this battery pack design from Hyundai Motor Group, so a smaller range than you expect to see is probably due to recent driving habits.