How to properly set up a network bridge between an Ubuntu 16.04 LTS VM and Windows 7 in VirtualBox?

Question

Computer networks

The problem is the following: when creating the above connection to the Internet with the participation of a router that gives a static IP, there are no problems. But the same procedure with a router that has/gives a dynamic IP ends with the message: " Disconnected Ethernet network".
How to fix it ?
PS NAT connection works without problems in both cases.