As @kezo says, there is a fault with the app, certainly for PHEV drivers. Even with the settings set to miles, not km, it will often express remaining EV range as km, whilst in the same screen showing petrol range in miles. I tried and failed to flag this to Hyundai, but they seemed incapable of understanding this! It’s patchy. Sometimes it quotes both in miles, other times as above. I’ve made sure that the settings are set to show miles (which they are) and even changes from miles to km and back again to see if that solves it, but it doesn’t.
This particular issue (allegedly) is “fixed” or worked around by refreshing the status of the car in the app. YMMV, i can’t test it – since it’s not an issue with the app itself, but its interaction with ccNC based systems.
Hyundai did accept that as an issue, i just saw a post of someone who got a mailed response by Hyundai that there be a software fix (the post was from dec 24) soon.
Similar the question to you, what version of app are you using – 2.0.24?
I can tell you that this is not a PHEV issue – users of ccNC Ioniq 5 have reported the same issue. Not very widespread, but the response by Hyundai was to a Ioniq 5 N owner.
Prior: SEAT Ateca Xcellence Lux 1.5 TSI DSG MY19, VW Golf GTE PHEV DSG MY23
Current: Hyundai Ioniq 6 Ultimate
Next: we'll see what's available in 2028.