Free monitoring doesn’t work on ipv6 only environment.
rs0 [direct: primary] test> db.enableFreeMonitoring()
Unable to get immediate response from the Cloud Monitoring service. Please check your firewall settings to ensure that mongod can communicate with 'https://cloud.mongodb.com/freemonitoring/mongo'
rs0 [direct: primary] test>
(To exit, press Ctrl+C again or Ctrl+D or type .exit)
rs0 [direct: primary] test>
root@engine-v6-only:~/hivesmartcontracts# host cloud.mongodb.com
cloud.mongodb.com is an alias for global.lb-f.td.aws.cloud.mongodb.com.
global.lb-f.td.aws.cloud.mongodb.com has address 34.230.213.36
It appears as if cloud.mongodb.com doesn’t have a v6 address.