SMTP configuration error 535 authentication Failed: Bad Username / Password

[redaER7]

Using chart grafana-7.3.0, I am looking to configure sendgrid SMTP inside chart values, my configuration is the following:

grafana.ini:
  smtp:
    enabled: true
    skip_verify: false
    host: smtp.***
    from_name: Grafana
    from_address: ***
smtp:
  # `existingSecret` is a reference to an existing secret containing the smtp configuration
  # for Grafana.
  existingSecret: "grafana-smtp-secret"
  userKey: "user"
  passwordKey: "password"

grafana-smtp-secret is the secret where user: is the service account I created, and password is for my SMTP config,
Checking the grafana.ini inside the pod, my infos are there

[smtp]
enabled = true
from_address = ****
from_name = Grafana
host = smtp.***
skip_verify = false

while secret values are present as environment variables GF_SMTP_USER GF_SMTP_PASSWORD

When testing, I'm getting error 535 authentication Failed: Bad Username / Password,
What am I missing here ?
Thank you,

[gmueller2000datev]

Did you restart grafana because see the comment under administration -> settings: "These system settings are defined in grafana.ini or custom.ini (or overridden in ENV variables). To change these you currently need to restart Grafana."