You have to hold it a few seconds to reset. An accidently quick push will not do anything. I have the gauges cluster setup to show the manual trip computer so that every time I recharge I do a rest so I can see how each charge is doing for range and efficiency. I only charge about once a week lately. I assume in winter than may go to twice a week.
Actually, for our Pure Electric P8 running AAOS, the user manual confirms this is just for the Trip Odomoter (via a long Press, indeed). But I think it resets all other values such a kWh/100 consumption as well.