Are you tracking your average mile/kWh? If you keep a track of that for your trips, you can then determine if you are running higher than most others and this would allow you to push the dealer to investigate. For example, it seems most IX owners are in the 2.5-3.5mile/kWh range depending on the driving style. But if you are always higher than this, then it could signal an issue with your vehicle that needs to be investigated.I would of I didn't loose tons of money for 3 months driving. UK not set up for EV yet. Most motorway charge only have limited superchargers, which are usually full up and when you finally plug in you pay extortionate rates for electricity.
I would love to know the secret. I think my battery is a pile of shit. Car lovely though.
In autumn I was getting 190 - 205 max on full 100% charge. My daily round trip to work is 32 miles but I am lucky if I get 4 days travel and only drive on A road and M25. I would love to drive fast but never exceed 70. So I am get 128 mile on a full charge. I do pre-warm, have sat Nav on and heat at 21 Deg. Help...
It also looks like some Youtube reviewers are using some sort of OBDII app to track more details on the battery for charge and discharge. So you could try to acquire a similar app and then track more details that way as well. It helps to have your own evidence to present to the dealer to investigate and they can also use this evidence to present to BMW on your behalf.