No need to add anything to /etc/network/interfaces
Instead, edit /etc/NetworkManager/conf.d/10-ignore-interfaces.conf. This file instructs NetworkManager to ignore all of the ethernet ports. Remove those entries.
/etc/NetworkManager/conf.d/10-ignore-interfaces.conf:
[keyfile]
unmanaged-devices=interface-name:br*
I don't know what br* is, so I left it in there.
Reboot and the network connects with DHCP as it should. Update /etc/network/interfaces if you need static addresses.
