Unable to Set MCOMEETADV license

Hi Team
I am trying to give MCOMEETADV license to a user.
Which is Audio Conferencing license in our O365 admin portal
User got already Skype for Business online plan.

Below are my Sku ID

PS C:\Script CSV> Get-MsolAccountSku

AccountSkuId                             ActiveUnits WarningUnits ConsumedUnits
------------                             ----------- ------------ -------------
CONTOSO1:VISIOCLIENT                    397         0            365
CONTOSO1:STREAM                         1000000     0            77
CONTOSO1:PROJECTCLIENT                  468         0            448
CONTOSO1:FLOW_P2                        1           0            0
CONTOSO1:POWERAPPS_INDIVIDUAL_USER      10000       0            9
CONTOSO1:POWER_BI_INDIVIDUAL_USER       100         0            26
CONTOSO1:POWER_BI_PRO                   5           0            5
CONTOSO1:ENTERPRISEPACKWITHOUTPROPLUS   5512        0            5274
CONTOSO1:SPZA_IW                        10000       0            0
CONTOSO1:WINDOWS_STORE                  1000025     0            0
CONTOSO1:ENTERPRISEPACK                 25912       0            25287
CONTOSO1:FLOW_FREE                      10000       0            2235
CONTOSO1:MICROSOFT_BUSINESS_CENTER      10000       0            2
CONTOSO1:MCOEV                          50          0            21
CONTOSO1:MCOPSTN1                       0           45           10
CONTOSO1:PBI_PREMIUM_P1_ADDON           1           0            0
CONTOSO1:POWERAPPS_VIRAL                10000       0            112
CONTOSO1:MCOPSTN_5                      6300        0            3962
CONTOSO1:DYN365_ENTERPRISE_P1_IW        10000       0            5
CONTOSO1:AX_FILE_STORAGE                1           0            0
CONTOSO1:Dynamics_365_Onboarding_SKU    10000       0            1
CONTOSO1:POWER_BI_STANDARD              1000000     0            2091
CONTOSO1:MCOPSTNC                       10000000    0            750
CONTOSO1:ENTERPRISEPREMIUM_NOPSTNCONF   26239       0            24770
CONTOSO1:EMS                            31631       0            29621
CONTOSO1:AX7_USER_TRIAL                 10000       0            3
CONTOSO1:MCOMEETADV                     26539       0            11593
CONTOSO1:PROJECTONLINE_PLAN_1           12          0            5
CONTOSO1:Dynamics_365_Hiring_SKU        10000       0            1
CONTOSO1:MCOPSTN2                       725         0            746
CONTOSO1:EXCHANGEENTERPRISE             1070        0            988
CONTOSO1:PROJECT_MADEIRA_PREVIEW_IW_SKU 10000       0            4
CONTOSO1:DYN365_ENTERPRISE_SALES        1           0            1
CONTOSO1:DYN365_ENTERPRISE_TEAM_MEMBERS 56          0            54
CONTOSO1:RIGHTSMANAGEMENT_ADHOC         10000       0            2
CONTOSO1:MCOSTANDARD                    300         0            38
CONTOSO1:PBI_PREMIUM_EM1_ADDON          1           0            0

Now When Iam tryin add license:

Set-MsolUserLicense -UserPrincipalName "adam.smith@contoso.com" -AddLicenses "CONTOSO1:MCOMEETADV"

I got result:

Get-MsolUserLicense : Unable to assign this license because it is invalid. Use the
Get-MsolAccountSku cmdlet to retrieve a list of valid licenses.
At line:1 char:1
+ Set-MsolUserLicense -UserPrincipalName "adam.smith@contoso.com" -AddLi ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : OperationStopped: (:) [Set-MsolUserLicense], MicrosoftOnline
   Exception
    + FullyQualifiedErrorId : Microsoft.Online.Administration.Automation.InvalidUserLicens
   eException,Microsoft.Online.Administration.Automation.SetUserLicense

my server connection is also fine

PS C:\Script CSV> Get-PSSession

 Id Name            ComputerName    ComputerType    State         ConfigurationName    Avai
                                                                                       labi
                                                                                       lity
 -- ----            ------------    ------------    -----         -----------------    ----
  1 WinRM1          ps.outlook.com  RemoteMachine   Opened        Microsoft.Exchange   ...

Everything looks right to me. That is exactly the same command I have used to license a user for that specific license (and others)

Have you tried on a different user, can you add other licenses? Have you tried disconnecting the session and reconnecting?