@JK_ 

Do you mean if there is a new device connecting to the VLAN of the network, and the number of the Client will not add on the controller page? 

If you are using the controller to set up the VLAN, I think you also have the SDN Switch in the network.

Can you describe the connection topology diagram and also send the screenshot to the Controller to determine the issue? And what is your controller version?

@John1234 I have configured 6 VLANs in router (6 in total, as per screenshot) and respectively in my 3 switches. I can see my devices assigned to the correct VLAN in the client information of OMADA SDN, but as you can see it is showing zero in the screenshot.

Model:

ER7206 v1.0

Firmware Version:

1.0.1 Build 20210113 Rel.35468

CPU Utilization:

1%

Switches: 

Model:

TL-SG2008P v1.0

Firmware Version:

1.0.1 Build 20210602 Rel.72106(Beta)

Controller Version:

4.3.5

Model:

OC200 1.0

Firmware Version:

1.8.2 Build 20210512 Rel.65838