Remove the default hostname of "~" as the nrsysmond.cfg.j2 has
#
# Option : override_hostname
# Type : string
# Value : Set to a non-empty value to use as the hostname that will be reported to New Relic
# Default: none
#
#hostname=newrelic.com
{% if newrelic_override_hostname|default(None) != None %}
hostname={{ newrelic_override_hostname }}
{% endif %}
Remove the default hostname of "~" as the nrsysmond.cfg.j2 has