These are extremely generic steps (did you even read this thread?) and are not guaranteed to resolve anything. There are far more troubleshooting steps to be performed with more complexity than just four things.
I applied those steps and issue get resolved at my end, just give an try and let's see
DNS is what I am guessing too.
VA and IaaS components should have the exact:
1. primary/secondary dns server
2. search domains -- order is critical too -- I've experienced connectivity issues when search domain order on the IaaS components is different than the vRA VA configuration. The first search domain must be the same on all components.