DELL FN2210S I/O MODULE cannot pass traffic from vCenter Distributed Switch

Hi All
I have a virtualization system configured as follows:

• Chassis: Dell FX2s with 2 × I/O Modules FN2210S (slot A1 & A2), Firmware version 9.14.1.16

• Host servers: 4 × Dell PowerEdge FC640 running VMware ESXi 7.0.3, managed by vCenter 7 with a Distributed Switch named Dswitch-02
  (This vCenter and Dswitch-02 setup is already working perfectly with other Dell R630 and R640 servers, so I believe the issue is not with vCenter or the Distributed Switch configuration.)

Network topology:

• Uplink FN2210S-01: Ports 11 and 12 connected to Core Switch 01 (LACP) – working fine

• Uplink FN2210S-02: Ports 11 and 12 connected to Core Switch 01 (LACP) – working fine

• Downlink connections:

  • Physical adapters:

    • vmnic0, vmnic2 on each ESXi host → FN2210S-141 (slot A1)

    • vmnic1, vmnic3 on each ESXi host → FN2210S-142 (slot A2)

  • Each ESXi host includes:

    • A vSwitch0 for the Management Network

    • A Distributed Switch (Dswitch-02) for virtual machine networks

Current Situation

• Both FN2210S modules are operating in their default mode.

• All internal ports are UP and fully VLAN-tagged.

• Uplink ports (11, 12 – LACP Port-Channel 128) are working normally.

• When VMs are connected to port groups on vSwitch0, they have normal external connectivity, confirming that VLANs and uplinks are configured correctly.

• However, when VMs are connected to networks on the Distributed Switch (Dswitch-02), they lose connectivity.

Example:

• VM01 (on FC640-01) and VM02 (on FC640-02) have internal IPs 192.168.1.11 and 192.168.1.22.

• When both are connected to the VLAN 11 port group on vSwitch0:

  • They can ping each other successfully.

  • They can also ping the external gateway 192.168.1.1.

• When both VMs are moved to the VLAN-11-DS02 network on Dswitch-02:

  • They cannot ping each other.

  • They cannot ping the external gateway 192.168.1.1.

Has anyone experienced this issue like me and how can I resolve it?

Any insights or suggestions would be highly appreciated.

Thank you very much!