I have at least a partial solution. You will need to do this for each extension. Here is what you do:
1. Login to 3CX Management
2. On the left side click on Extensions and open up that tree.
3. Again on the left click on one of the extensions.
4. On the right side click on the Forwarding Rules tab.
5. Under the General Forwarding Options section, click on the radio button beside Use PBX Status and click OK to save changes.
This will stop the pages from ringing back to the phone you are paging from but then if you are on a call and a second call comes in you won't see with it set to Use PBX Status.
Don't know if this helps or not.