Missing parameter ActiveSyncBlockedDeviceIDs for Set-CASMailbox command

Question

We have an automated powershell script which monitors devices and blocks or allows mailbox access based on certain criteria.

This script has been working fine till date, but for one of our customers we get an error message that 'ActiveSyncBlockedDeviceIDs is an un recognised parameter for command Set-CASMailbox'

The command used is as follows :
Set-CASMailbox -Identity <emailAddress> -ActiveSyncAllowedDeviceIDs @{Add = <easDeviceId> } -WarningAction 'SilentlyContinue'

We tried running the same directly from powershell as well, but still got the same error.

Things we checked :
mailbox has active license, has EAS enabled, user is able to successfully send and receive mails.

Please advise on the above. Is there any case where blocking is not allowed or is it an actual issue?

Permission given to Oauth app - Exchange.ManageAsApp
Assigned role - Exchage Administrator

Answer 1

Works here. Does it only fail for that customer?