For the first case – when using public connectivity – please read the following https://blog.couchbase.com/autonomous-operator-1-2-0-public-connectivity/ as that will tell you how to debug internet issues and hopefully find a root cause. That should give us more to go on.
In general the documentation for 2.0 is much better around networking https://docs.couchbase.com/operator/2.0/concept-couchbase-networking.html. Although the data structures have changed, the core behavior has not. See if they are more helpful…
Let us know how you get on and we can delve deeper if needs be.