Can't enable Siri in High Sierra? When I click &quot;Enable Ask Siri&quot; in the Siri Preferences Panel

I get a message saying Siri sends information like your voice input, contacts, and location to Apple to process your request
I click Enable
The dialog dismisses, and Enable Ask Siri is still unchecked.

Why is this happening, and how can I fix it? Note I've rebooted, and ensured Notification Center is enabled, as mentioned in things I see when googling about this issue.
Note that this is a work computer, so it may have this feature disabled in some way? I have another work computer that it works fine on, both running High Sierra.
Here are the log messages from the Console.app
error   12:20:48.173926 -0300   siriknowledged  -[CKEventHandler setupNotifyHandlers]_block_invoke Received XPC event from notifyd: &lt;private&gt;
error   12:20:48.181428 -0300   siriknowledged  -[CKEventHandler setupNotifyHandlers]_block_invoke Received XPC event from notifyd: &lt;private&gt;
default 12:20:48.183930 -0300   suggestd    PPPortrait read Siri as disabled.
default 12:20:48.184209 -0300   silhouette  PPPortrait read Siri as disabled.
default 12:20:48.194735 -0300   suggestd    PPPortrait read Siri as disabled.
default 12:20:48.194972 -0300   silhouette  PPPortrait read Siri as disabled.
default 12:20:48.200372 -0300   suggestd    PPPortrait read Siri as disabled.
default 12:20:48.205963 -0300   suggestd    PPPortrait read Siri as disabled.
default 12:20:49.271304 -0300   SiriNCService   remote_device_copy_unique_of_type: device not found
default 12:20:49.271532 -0300   SiriNCService   remote_device_copy_unique_of_type: device not found
For me, turns out IT at our company has disabled Siri as a corporate policy, at least according to our tech support.

Why it works on a corporate laptop and not a corporate desktop, both running High Sierra, I'm not sure!