Can't get Centralized pipeline management working in ELastic Cloud X-pack

Question

I'm trying to set Centralized pipeline management but it is still not working.

I'm using Elastic Cloud trial version and Logstash running on a local vm

my logstash.yml looks like:

xpack.management.elasticsearch.url: "https://xxx.eu-central-1.aws.cloud.es.io:xxx/"
xpack.management.enabled: true
xpack.management.elasticsearch.username: elastic
xpack.management.elasticsearch.password: password
xpack.management.logstash.poll_interval: 5s
xpack.management.pipeline.id: ["apache", "cloudwatch_logs"]
cloud.auth: "elastic:xxxx"
cloud.id: "yyyy=="
path.data: /var/lib/logstash
path.logs: /var/log/logstash

I followed instructions from https://www.elastic.co/guide/en/logstash/6.x/logstash-centralized-pipeline-management.html#logstash-centralized-pipeline-management and https://www.elastic.co/guide/en/logstash/6.x/configuring-centralized-pipelines.html

But Logstash isn't shipping anything to Elastic if I set manually a conf file and pipeline on logstash vm (whereas these were working fine on hosted trial) and If I create new pipeline in from Kibana UI...nothing else happen than having my pipeline saved under logstash pipeline management

Any tip? Did I miss some steps?