Here's the behavior:
1. If at the AP, VLAN is enabled, then Management VLAN will be enabled.
2. This means that if your SM is registered with the AP, you have to be in the management VLAN to access the SM. for example, if your management VLAN ID is configured to be 31, in order to connect to the SM locally at the SM side, your management device need to be VLAN tagged for 31.
3. However, if your SM is not connected to the AP, you will need to access the SM management untagged!