Disable MDM contacts syncing

I have an iPhone enrolled in MDM via a work account. I found that once I had signed into the work account, all of the work contacts would show up in Messages.

E.g.

• Go to Messages
• Start a new message
• Type "emma" into the receiver field
• Every "emma" at work (and from my personal contacts) shows in the autocomplete dropdown

I would like to disable the work contacts so that they do not show up in iMessage.

I tried:

• Show or hide a Contact list
  • only my personal contacts ("All iCloud") was listed here
• Remove contacts account
  • Settings > Apps > Contacts > Accounts > Work account takes me to the general Work account page, which does not have a Contacts toggle
  • in Settings > Apps > Contacts > Accounts, the Work account in the list even says "Inactive"
• in Work account > iCloud toggled off Contacts iCloud syncing
  • also tried toggling off every toggle in iCloud syncing. no change

The only thing that has worked is signing out of the MDM account, which I can't do long term.

Is there a way to disable to the work contacts? I can't even see them anywhere other than the Messages autocomplete. Is it administrator-controlled (IT is saying no).