After you have configured an interface to be of type VLAN, the next step is to edit it and associate VLAN IDs with it. You will want to define here all the VLANs whose traffic you anticipate will traverse this interface.
The expectation is that you will see traffic from multiple VLANs. (If not, it would be simpler to leave the interface as type Dedicated and apply a single policy, or consider a CIDR sub-interface instead).
You can specify VLAN values by Range from or by IDs.
.png)