MS510TXM - Private VLAN Promiscuous Port Issue

Hello,

I am following the directions on how to properly setup a promiscuous port on a private vlan that allows communication between the two associated community ports. I am unable to add more than one secondary vlan in the interface and the manual clearly says it's possible so I must be missing some nuance. 

VLAN Type Configuration

20 - Primary

21 - Community

22 - Community

Private VLAN Association

Primary 20 --- Secondary 21-22 --- Community 21-22

Port Mode Configuration

I8 - Promiscuous (LAG)

Private VLAN Promiscuous Interface Configuration

Here is page 180 of the manual under:

Private VLAN promiscuous interface: Assign the interface to primary and secondary VLANs

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9. In the Promiscuous Primary VLAN field, specify a primary VLAN ID. You can select a VLAN for which you configured the type as Primary (see Assign a private VLAN type to a VLANonpage171).

10. In the Promiscuous Secondary VLAN field, specify one or more secondary VLAN IDs. You can specify VLANs for which you configured the type as Isolated or Community, both of which are secondary VLAN types within a private VLAN. You can specify a single VLAN ID, a range of VLAN IDs, or a combination of both in sequence separated by a comma (,):

You can specify an individual VLAN ID, such as 10. 

You can specify the VLAN range values separated by a hyphen, for example, 10-13. • You can specify a combination of both separated by commas, for example: 12,15,40–43,1000–1005, 2000.

ERROR

Error: Value (0) is out of range for 'Promiscuous Secondary VLAN'. The valid range is 2 to 4095.

I have tried to add 2 secondary vlans with the comma approach 21,22 and with the hyphen approach and both give the same error. The Secondary VLAN field only accepts 1 vlan so how do you configure a promiscuous port in a private vlan?