netplan apply results in connectivity loss on already configured interfaces

I have following config:

network:
  version: 2
  renderer: networkd
  ethernets:
    ens3:
      dhcp4: no
      addresses:
        - 192.168.29.11/24
      nameservers:
          addresses: [192.168.22.252, 192.168.22.254]
      routes:
        - to: 0.0.0.0/0
          via: 192.168.29.221
          table: 100
      routing-policy:
        - from: 0.0.0.0/0
          table: 100
          mark: 1

It works.
Than I want to add interface, let's say:

  tunnels:
    gre1:
     mode: gre
     local: 192.168.204.1
     remote: 192.168.204.4
     mtu: 1396
     addresses:
      - 192.168.200.178/30

Then I run netplan apply .

And I loss ssh connection, because ens3 is restarted, I have to wait ospf reconnect.
Why? If there no changes, why interface is restarted?
This is wrong!