I think it's far more likely that the sevcon odometer is not calculating correctly. I don't think the sevcon odo value is used for anything, the Zero components get motor shaft revolutions and use a formula to determine the odometer. All bikes with the same controller get the same sevcon FW, regardless of wheel size and gear ratio, which are critical to know when calculating distance traveled.
I would note down the odo values, ride it a short distance(maybe 5 mi) and then record the values again. See if the values changed the same amount. If not, you have the answer.
What was the manufacturing date on the frame? The frame manufactured date probably isn't the same as the shipped date, supply chain delays have made that more probable too. If Zero orders bike frames in one or two bulk orders, that date could be way off the actual manufactured date. Zero HQ will tell you the date when the bike rolled off the line if you call and ask politely. Not sure if you're in the US or not, but if you aren't I've heard it takes 1-2 months to get something shipped via boat now.
Finally, warranty start date occurs when the bike is registered by the dealer as sold to a customer with Zero, or (for a demo) when the bike was manufactured. Zero HQ can tell you if your bike was a demo, and when their records say the warranty starts and ends. What told you when your warranty date expired? If it's any dealer paperwork, then Zero HQ would never have seen it, and only cares what their system says anyway.
I get that you're concerned, but I suspect it's unwarranted. Zero assumes that people won't be reading their serial data, and some things are half baked/not accurate/require additional context. The other thing that comes to mind is the battery cycles number and the state of health value, both of which are not representative or possibly not working. It'd be nice if they told us though.