Unable to SSH to Ubuntu Server after changing the MTU size to 1550

The Current Setup consists of a virtual router managing the VLANS 201, 401, 601 and routing traffic between the VLANs and the external network. Device A is connected to the virtual router via a switch.

Switch Configuation

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

Devices Connected to the Switch

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

Note: The virtual router is a bare metal system running Ubuntu 22.04 server.

Netplan for the virtual router

network:
  version: 2
  renderer: networkd
  ethernets:
    eno1:
      addresses:
      - 10.1.1.12/24
      routes:
      - to: 0.0.0.0
        via: 10.1.1.251
        metric: 100
      nameservers:
        addresses:
        - 10.1.1.23
        - 10.1.1.22
    enx7cc2c6436994:
      dhcp4: false
      mtu: 1550
      addresses:
      - 10.2.1.1/16
      routes:
      - to: 0.0.0.0
        via: 10.4.1.251
        metric: 100
      nameservers:
          addresses:
          - 10.2.1.1
  vlans:
    vlan.401:
      id: 401
      dhcp4: false
      mtu: 1550
      addresses:
      - 10.4.1.1/16
      routes:
      - to: 0.0.0.0
        via: 10.4.1.1
        metric: 100
      link: enx7cc2c6436994
    vlan.601:
      id: 601
      dhcp4: false
      mtu: 1550
      addresses:
      - 10.6.1.1/16
      routes:
      - to: 0.0.0.0
        via: 10.6.1.1
        metric: 100
      link: enx7cc2c6436994

DHCP configuration for the Virtual Router Router

option domain-name-servers 10.4.1.23, 10.4.1.22, 8.8.8.8, 8.8.4.4;

default-lease-time 600;
max-lease-time 7200;

ddns-update-style none;

subnet 10.2.0.0 netmask 255.255.0.0 {
option broadcast-address 10.2.255.255;
range 10.2.1.1 10.2.255.254;
option routers 10.2.1.1;
}

subnet 10.4.0.0 netmask 255.255.0.0 {
option broadcast-address 10.4.255.255;
range 10.4.1.1 10.4.1.254;
option routers 10.4.1.1;
}

subnet 10.6.0.0 netmask 255.255.0.0 {
option broadcast-address 10.6.255.255;
range 10.6.1.1 10.6.1.254;
option routers 10.6.1.1;
supersede mtu 1550
}

Netplan configuration on Device A

network:
  version: 2
  renderer: networkd
  ethernets:
       interface_A:
          dhcp4: false
       interface_B:
          dhcp4: false
          mtu: 1550
  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

DHCP client configuration on Device A

option rfc3442-classless-static-routes code 121 = array of unsigned integer 8;

send host-name = gethostname();
request subnet-mask, broadcast-address, time-offset, routers,
        domain-name, domain-name-servers, domain-search, host-name,
        dhcp6.name-servers, dhcp6.domain-search, dhcp6.fqdn, dhcp6.sntp-servers,
        netbios-name-servers, netbios-scope, interface-mtu,
        rfc3442-classless-static-routes, ntp-servers;

Observed Behavior:

• I am able to ping Device A using 10.6.1.2 and 10.4.1.2. However I can only ssh into device using the 10.4.1.2 ip address. I am unable to ssh into device A using the 10.6.1.2 ip address.
• Changing mtu size of interface_B to 1500 seems to resolve the issue. However, I need to configure the mtu of interface_B to 1550