Hi Anton,

If I do a $  docker run janusgraph/janusgraph:latest
the logs show it runs with the berkeleyje backend.

If I look at:
https://github.com/JanusGraph/janusgraph-docker/blob/master/0.5/Dockerfile
and your docker compose file, I can not see how you make your janusgraph containers use the scylla/cql backend. So, check the logs of your janusgraph containers to see what they are running.

And, if this was not clear, sharing configured graphs between janusgraph instances is only possible if they share a distributed storage backend. If berkeleyje is used, each janusgraph container has its private storage backend.

Best wises,    Marc