Unpair two iPhones?

No, something changed with a setting you made. Go to Settings/Messages/Text Message Forwarding and turn it off. But you should never use a personal Apple ID on a work phone, because that means all personal content is actually owned by the company.

SurgingWaters wrote:

I do and it hasn’t been an issue for 3 years.. ? Maybe something changed with an upgrade?

What you are encountering is normal and expected behavior.

You can either shut off parts of iCloud (or shut it off again, if something was unexpectedly re-enabled), or preferably can switch to a second Apple ID.

Mixing work and personal data and iCloud data often gets gnarly, and data sharing and notifications and the rest all happen when an Apple ID is shared.

Here is what you are meeting up with: macOS - Continuity - Apple

Make separate apple ids or log into a work account on your work device through searching for “vpn’s and device management” in settings

[Edited by Moderator]

Do you have the same Apple ID on both phones? That might be an explanation.