I’ve got a couple of Zigbee plugs, all work well, except one I use for the washing machine. It randomly turns off. When I check the history in HA, it just says that it turns off, no source. My guess is that it trips, ie temporarily exceeds 10A. The plugs are rated 10A from Aliexpress.
If it is a power tracking one you should be able to see if it’s being overloaded. Unplug the washer and see if it still turns off if it does then something is turning it off. I really trust the sonoff ones that I flash with tasmota, they are WiFi but they are rock solid and offline. They make zigbee ones too. The sonoff one on my all in one washer never has had a problem.