I’m seeing the same behavior on my two VZM30-SN’s. One for an 18W bathroom fan (7.9kWh after running for ~12 hours), and one for ~150W of garage lighting (112kWh after a few weeks of intermittent usage).
It looks like this bug was also seen during development: Zigbee On/Off Switch | Project Vernacular - #45 by dougl
I’m running “raw” zigbee2mqtt with no HA, so I don’t think HA is a possible factor. Unsure whether there’s a conversion issue with how z2m parses the value, or a firmware issue down on the switch.
BTW: curious as to how the accumulator data gets stored on the switch so that it doesn’t wear out the flash/EEPROM with excessive write cycles?