Ah. I see. We’re running discourse_docker with linked web and data containers, so Redis is running within our data container.
Within our data container:
# redis-server --version
Redis server v=5.0.5
So, that explains it. It looks like we need to upgrade our data container as well. That makes me more nervous. When was that requirement added? Maybe I could revert to a previous version of the web container until my reinforcements (in Australia) are awake & available. 