Skype Add-In gets disabled when switching multiple accounts(guest) between MS Teams

Hi Say_Much 

Running this PowerShell script will add an access rule to DENY the current user the right to SetValue on this registry key. Then Teams (running in current user's context) won't be able to change the value anymore and the Outlook-plugin stays enabled. 

$regPath = 'Registry::HKCU\Software\Microsoft\Office\Outlook\Addins\UCAddin.LyncAddin.1'

Set-ItemProperty $regPath -Name LoadBehavior -Value 3

$acl = Get-Acl $regPath
$acl.Access | FT *

$idRef = [System.Security.Principal.NTAccount]([System.Security.Principal.WindowsIdentity]::GetCurrent().Name)
$regRights = [System.Security.AccessControl.RegistryRights]::SetValue
$inhFlags = [System.Security.AccessControl.InheritanceFlags]::None
$prFlags = [System.Security.AccessControl.PropagationFlags]::None
$acType = [System.Security.AccessControl.AccessControlType]::Deny

$rule = New-Object System.Security.AccessControl.RegistryAccessRule ($idRef, $regRights, $inhFlags, $prFlags, $acType)

$acl.AddAccessRule($rule)

$acl | Set-Acl -Path $regPath

$acl = Get-Acl $regPath
$acl.Access | FT *

I think it's pretty simple, because, when you switch to a guest account, as mentioned in article guest user does not have permission to schedule a meeting. Since the guest account does not have permission to schedule a meeting, Outlook might be disabling the add-in. Another reason could be, in SFB you needed same account in Skype and Outlook to schedule a meeting. Same would be carried over in Teams. Since the user account in Teams and Outlook are different, add-in is disabled.