Yep, it’s a device characteristic. Much discussion in the forums. There are some smart apps that people have written to address this, but they require that you have a device that knows when it’s been restored to power.
People used to use the generation one smartthings motion sensor for this, because it would switch itself from mains power to battery power and back and you could capture those changes. I don’t know what devices people are using for that now but I would ask in the smartapp thread. (this is a clickable link)