It appears that ufw and docker do not work well together out of the box.
This is a common enough problem that we should have some general advice on it.
From a related note: One solution I found for easy docker setups was in the docker daemon setting {"iptables": false} to disable the docker override. As long as you then explicitly allow 7075 on ufw the node works well.
It appears that ufw and docker do not work well together out of the box.
This is a common enough problem that we should have some general advice on it.
Related link (which doesn't have any easy answers):
https://stackoverflow.com/questions/30383845/what-is-the-best-practice-of-docker-ufw-under-ubuntu
Comment from @zhyatt: