Using AppleiD on 2 Devices without sharing Call Log?

Hi,

I am using my personal Apple iD on 2 iPhones - an iPhone 7 (personal) and iPhone 5s (work) as I need to have my work device connected to my in-car hands-free during business hours (I travel a lot for work) but I also want to listen to my own music (I use Apple Music).

So, I use my Apple id on both which is fine except the call logs on both phones show all calls received on both phones. So, if I receive a call on my work phone - it only rings on that device but it will also show in my personal phone's call log (and vice-versa).

I have removed each number from the 'other' phone in the settings, I have switched off iMessage and Calls on Other Devices. Also, I use Family Sharing (I'm not the host).

I have run out of ideas now and any help would be appreciated!

Thanks,