2. Run Psping to the Managed instance name with Port 1433 . In case it does not work something is wrong with the communication between the 2 Vnets:
In this case , you should check that there is NSG ( Network security group ) rule on the Subnet of the other Vnet ( the Vnet where you are trying to connect to managed instance from ) The rule need to be configured as the following :
Source IP addresses : The subnet range of IP's where the VM with SSMS is located
Destination IP addresses : The MI subnet range of IP's
This is outbound rule and must have higher priority then rule that would eventually block the connection
P.S - Very soon we are also going to support NSG on port 1433 on Manage instance subnet.