Desk phones not showing main company number as caller ID but same Ext. in Phone App does

[DeeNile]

We have Audiocodes C450HD phones working with Zoom. We have a published main number set up as the main for the company, and we want all calls to go outbound with this number for Caller ID.  All the settings are correct in the Zoom Admin section. If we make calls from the phone instrument, it always shows the caller ID of that instrument's direct dial number, not the caller ID of the main company number.
If the same user/extension calls using their computer App based soft phone, the main company number caller ID option is chosen and can be changed. This gives the desired effect: the user calls as the main company number.
Why doesn't the physical telephone instrument act the same way as the soft phone: by default dial with the caller ID of the main number? Is there a setting missed somewhere?