No internet access on Ubuntu server when connected to Trunk port

I have ubuntu server configured as a virtual router for routing traffic from the isolated VLANs 10.2.0.0/16 (VLAN 201), 10.4.0.0/16 (VLAN 401) and 10.6.0.0/16 (VLAN 601) to the external network 10.1.1.1/24. The virtual router has 2 ethernet interfaces.

Interface A -> Connected to the external network. Interface B -> Connected to a 802.1q managed switch via a tagged port.

Switch Configuation

VLAN 201
  - Tagged Port: 1
VLAN 401 
  - Tagged Port: 1 
  - Untagged Ports: 2
VLAN 601
  - Tagged Ports: 1, 3

Devices Connected to the Switch

Port 1 -> Virtual Router 
Port 2 -> Device A
Port 3 -> Device A

Note: Device A is connected to both Port 2 (VLAN 401) and Port 3 (VLAN 201) via two separate ethernet interfaces.

Current netplan Configuration on Device A

network:
  version: 2
  renderer: networkd
  ethernets:
       interface_A:
          dhcp4: false
       interface_B:
          dhcp4: false
  bridges:
      cloudbr0: 
          addresses: [10.4.1.2/16]
          routes:
          - to: 0.0.0.0/0
            via: 10.4.1.1
            metric: 100
          nameservers:
                  addresses: [8.8.8.8,8.8.4.4]
          interfaces: [interface_A]
          dhcp4: false
          dhcp6: false    
      cloudbr1: 
          addresses:  [10.6.1.2/16]
          routes:
          - to: 0.0.0.0/0
            via: 10.6.1.1
            metric: 1000 
          nameservers:
                  addresses: [8.8.8.8,8.8.4.4]
          interfaces: [interface_B]
          dhcp4: false
          dhcp6: false

With the current configuration I have network connectivity on interface_A, however I have no network connectivity with interface_B.

Observed Behavior:

• Changing Port 3 from tagged to untagged on the switch seems to resolve the issue.

However, I am running Cloud Stack with isolation type of VLAN on the Devices, as a result additional VLANs will be created on the 10.6.0.0/16 network in the future.

Any suggestions on how to modify the netplan so that Device A can support tagged traffic on interface_B would be greatly appreciated.