I can’t find anything about this in the release notes, but my HA logs don’t lie. Beware, 2021.7 to 2021.8 requires an update to zwavejs. I’m sure in some configurations that isn’t an issue, but it cause problems in my docker deployment. My compose file uses the homeassistant/home-assistant:stable image and zwavejs/zwavejs2mqtt:latest. As of today, they are incompatible. I got my home back up by changing to homeassistant/home-assistant:2021.7
Sounds like you didn’t pull a new zwavejs2mqtt image. 2021.8 is compatible with the latest zwavejs2mqtt.
Ok. I guess I still have a lot to learn about docker. Thanks for helping me improve there. Either way, it still seems insane that the release notes don’t very obviously state a required interface update
The command you’re looking for is the following:
sudo docker-compose pull && sudo docker-compose down && sudo docker-compose up -d
this will update (pull) the image, bring the container down, and then start it back up for you.
You can skip the down, docker-compose pull && docker-compose up -d, then it won’t take down the container unless a new image was actually pulled.
True, I usually do it this way to be sure it’s recreated 
or just use portainer and ‘recreate’ container and click the slider for download new image (for the non-compose docker users)