Yes, you are right. I just got off the phone with Apple support. Things are designed to work like this. My understanding is that it is due to iCloud account. The iCloud account is connected to the Apple ID any device with the same cloud/Apple ID will have integrated phone call logs and voicemails. But you should only receive the calls and be able to answer them on the individual phone. But you can listen to the voicemails across all devices.
So then I asked support if I could turn off my iCloud account and completely delete it but the support technician told me you basically cannot have working subscriptions and apps if you do not have an iCloud account. Even if I deleted it and deactivate it now anytime I want to download a new app or purchase a new song I would have to reactivate my iCloud.
So then I told support that I have had the same Apple ID with both my parents for as long as I can remember. I am 33 and I have shared an ID with them for decades at least two or 1.5… Long before family sharing came along. Because my parents never had an email. So I didn’t see the point in making them their own email and then Apple ID/iTunes account. Fast forward 10 + years later to today the issue came up when I started seeing all of my mom’s calls and voicemails on my phone. So yes it is ios17 that started the problem. Prior to the update turning off phone in the icloud setting would solve the issue but apple has done away with that.
Yes, I can create them a new Apple ID and do family sharing with them. Unfortunately, they moved last year to another state. They are technology deficient in order to set up their new IDs and family sharing. I would have to fly to them and set it up for them, if I do it via screen sharing, it would literally take days in order to log off my Apple ID and set up their whole new Apple ID and family sharing.
I mean I got them an Apple iPhone for convenience. Being able to track them and share certain things I want to share with them but this is not so convenient so the Apple iPhone no longer serves the purpose it did
Yes, for other people wondering I have everything else turned off.Like I told support, I have call forwarding off,I have phone set to off in the iCloud, I have phones set to only receive at their current number, I also have handoff shut off on all devices (not my first rodeo).
The support tech was really friendly and offered to help me set up family sharing and create new IDs for my parents via screen share.
To make the story short, each device should have their own Apple ID/Apple account whatever you wanna call it, through family sharing or etc…
hopefully this post helps someone else.