step execution is handled by the runner. have you checked to ensure you are using the latest version of the runner? The latest stable version of the docker runner is drone/drone-runner-docker:1.5.3.
If the problem is not resolved by using the latest runner, we would ask you to provide a full yaml that can be used to reproduce. There is some important information missing from the yaml you provided (such as the pipeline type) and having a full yaml to reproduce can make things easier for us. Lastly, we would kindly ask for your full runner logs with trace logging enabled.
Also, if you are using the kubernetes runner, please keep in mind the kubernetes runner is in Beta and is still being actively developed and may not be suitable for production use (it seems to work better on some kubernetes distros / managed providers than others). For production use, we recommend the Docker runner.