pmm-agent Failed to connect to pmm

I installed Percona PMM with Docker and it’s up and running on the PMM server:

root@cop:~# docker psCONTAINER ID        IMAGE                  COMMAND                CREATED             STATUS                       PORTS                                         NAMES
6459173799da        percona/pmm-server:2   "/opt/entrypoint.sh"   About an hour ago   Up About an hour (healthy)   0.0.0.0:8080->80/tcp, 0.0.0.0:8043->443/tcp   pmm-server

I configured Nginx as reverse proxy with SSL and a trusted SSL certificate and I can correctly access to Grafana if I access to https://pmm.my.domain.I installed PMM Client on a MySQL machine, I configured it to connect to the PMM Server but I receive some connection timeouts and I cannot understand why.
My PMM Client version is:

root@mysql3-staging:~# pmm-admin --version
ProjectName: pmm-admin
Version: 2.9.0
PMMVersion: 2.9.0
Timestamp: 2020-07-14 10:11:43 (UTC)
FullCommit: cae4d06914b68bb625e9ff7dcd2d7baf3cac9227

I configured PMM Client to connect to https://pmm.my.domain:443:

root@mysql3-staging:~# pmm-admin config --force --server-url=https://admin:password@pmm.my.domain:443
Checking local pmm-agent status...
pmm-agent is running.
Registering pmm-agent on PMM Server...
Registered.
Configuration file /usr/local/percona/pmm2/config/pmm-agent.yaml updated.
Reloading pmm-agent configuration...
Configuration reloaded.
Checking local pmm-agent status...
pmm-agent is running.

PMM Client is running:

root@mysql3-staging:~# ps ax|grep pmm
22986 ? Ssl 0:00 /usr/sbin/pmm-agent --config-file=/usr/local/percona/pmm2/config/pmm-agent.yaml

But I cannot add a new MySQL source:

root@mysql3-staging:~# pmm-admin add mysql --query-source=slowlog --username=pmm --password=password
Failed to get PMM Server parameters from local pmm-agent: pmm-agent is running, but not set up.
Please run `pmm-admin config` with --server-url flag.

I then checked that PMM Client cannot connect to PMM Server:

Jul 31 10:02:24 mysql3-staging systemd[1]: Started pmm-agent.
Jul 31 10:02:24 mysql3-staging pmm-agent[24447]: #033[36mINFO#033[0m[2020-07-31T10:02:24.078+02:00] Loading configuration file /usr/local/percona/pmm2/config/pmm-agent.yaml. #033[36mcomponent#033[0m=main
Jul 31 10:02:24 mysql3-staging pmm-agent[24447]: #033[36mINFO#033[0m[2020-07-31T10:02:24.079+02:00] Using /usr/local/percona/pmm2/exporters/node_exporter #033[36mcomponent#033[0m=main
Jul 31 10:02:24 mysql3-staging pmm-agent[24447]: #033[36mINFO#033[0m[2020-07-31T10:02:24.079+02:00] Using /usr/local/percona/pmm2/exporters/mysqld_exporter #033[36mcomponent#033[0m=main
Jul 31 10:02:24 mysql3-staging pmm-agent[24447]: #033[36mINFO#033[0m[2020-07-31T10:02:24.079+02:00] Using /usr/local/percona/pmm2/exporters/mongodb_exporter #033[36mcomponent#033[0m=main
Jul 31 10:02:24 mysql3-staging pmm-agent[24447]: #033[36mINFO#033[0m[2020-07-31T10:02:24.079+02:00] Using /usr/local/percona/pmm2/exporters/postgres_exporter #033[36mcomponent#033[0m=main
Jul 31 10:02:24 mysql3-staging pmm-agent[24447]: #033[36mINFO#033[0m[2020-07-31T10:02:24.079+02:00] Using /usr/local/percona/pmm2/exporters/proxysql_exporter #033[36mcomponent#033[0m=main
Jul 31 10:02:24 mysql3-staging pmm-agent[24447]: #033[36mINFO#033[0m[2020-07-31T10:02:24.079+02:00] Using /usr/local/percona/pmm2/exporters/rds_exporter #033[36mcomponent#033[0m=main
Jul 31 10:02:24 mysql3-staging pmm-agent[24447]: #033[36mINFO#033[0m[2020-07-31T10:02:24.079+02:00] Starting local API server on http://127.0.0.1:7777/ ... #033[36mcomponent#033[0m=local-server/JSON
Jul 31 10:02:24 mysql3-staging pmm-agent[24447]: #033[36mINFO#033[0m[2020-07-31T10:02:24.085+02:00] Starting... #033[36mcomponent#033[0m=client
Jul 31 10:02:24 mysql3-staging pmm-agent[24447]: #033[36mINFO#033[0m[2020-07-31T10:02:24.085+02:00] Connecting to https://admin:***@pmm.my.domain:443/ ... #033[36mcomponent#033[0m=client
Jul 31 10:02:25 mysql3-staging pmm-agent[24447]: #033[36mINFO#033[0m[2020-07-31T10:02:25.087+02:00] Started. #033[36mcomponent#033[0m=local-server/JSON
Jul 31 10:02:29 mysql3-staging pmm-agent[24447]: #033[31mERRO#033[0m[2020-07-31T10:02:29.085+02:00] Failed to connect to pmm.my.domain:443: timeout. #033[31mcomponent#033[0m=client
Jul 31 10:02:29 mysql3-staging pmm-agent[24447]: #033[36mINFO#033[0m[2020-07-31T10:02:29.884+02:00] Connecting to https://admin:***@pmm.my.domain:443/ ... #033[36mcomponent#033[0m=client
Jul 31 10:02:34 mysql3-staging pmm-agent[24447]: #033[31mERRO#033[0m[2020-07-31T10:02:34.884+02:00] Failed to connect to pmm.my.domain:443: timeout. #033[31mcomponent#033[0m=client
Jul 31 10:02:36 mysql3-staging pmm-agent[24447]: #033[36mINFO#033[0m[2020-07-31T10:02:36.361+02:00] Connecting to https://admin:***@pmm.my.domain:443/ ... #033[36mcomponent#033[0m=client

The MySQL server (on which PMM Client is installed) can correctly reach https://pmm.my.domain (checked with telnet, curl and elinks).
Could you help me please?
Thanks!

Terribly sorry we missed this and no one has responded yet…I looked over your steps and they seem to all be correct.  Can you run ‘pmm-admin status’ and post the output.  Just curious if all connections to PMM Server are impacted or just for the registration action.  Also, instead of FQDN, can you try adding MySQL monitoring by IP address to see if that works (might isolate where in the code we’d need to look if it’s a bug).  And just to be complete…I see you’re running client 2.9.0 is that the container version as well “docker exec -it pmm-server curl -u admin:admin http://localhost/v1/version”.