WARNING - Couldn't gather 1 keys, rescheduling even with --contact-address flag

I'm trying to deploy dask on an AWS Fargate cluster, and am starting workers with the following command:
```
dask-worker --preload /app/common.py tcp://dask_scheduler_service.local:8786 --contact-address tcp://dask_worker_service.local:9000 --listen-address tcp://0.0.0.0:9000
```
The `dask_scheduler_service.local` and `dask_worker_service.local` names are from the service discovery service (cloud map).

I'm able to create a client, submit a job and track its progress on the dashboard. When the workers complete all the tasks, I get a
`WARNING - Couldn't gather 1 keys, rescheduling`
message from the client, and this error from the scheduler:
`ERROR - Workers don't have promised key: ['tcp://xxx.xx.xx.xxx:9000'],`
with the IP of the worker (and not `dask_worker_service.local`)

Anything obvious I'm missing?