I've had an I-Pace for a few months now and noticed the range was 325km instead of over 400km as it should be (I had a loaner recently and it was reading 425km) - I'm in Norway. Thought it may be down to my driving style, but I took it easy and no change. Then, 2 weeks ago, a colleague said he'd had the same problem, it was a software issue, and he'd had it fixed. Check to see if the range changes when you switch between normal and economy modes. It should, but mine doesn't and neither did his before he got the software fix.
So....I took it to the dealer this week to get this and the re-gen braking recall problem fixed, but they couldn't fix the range. They told me they had an update on one PC, but they couldn't load it to the car as it had got corrupted (something along those lines). They are now waiting on Jaguar to send them another patch, but - and this may be the underlying problem - he told me they probably needed many dealers to report the same issue before they'd get the fix they needed. They'd had 4 cars in the same day with same issue!
Reading other threads, I'm starting to suspect that Jaguar do not have sufficient resources to provide the support needed, and that their dealers are struggling with not having enough knowledge yet on this new technology to problem solve effectively - again with a lack of support from head office.
Not good selling a car with a quoted range much longer than it delivers. The dealer told me the low range was real, so don't push it - it's something to do with not using the whole of the battery capacity.