Ubuntu 18.04 AMI with "ubuntu-desktop" pkg fails to connect (networking)

The problem can be duplicated easily with the following steps:

• launch ubuntu 18.04 instance
• apt install ubuntu-desktop
• create an AMI from this instance
• launch a new instance from AMI and fail to connect via ssh

Looking at the system log, it is obvious that the network interface ens5 was not started properly. Its status is shown as "down". See image attached.

Any ideas? The original instance still works fine in terms of networking.