RCS and SMS on MacBook Pro

I currently have a 14" MacBook Pro (M3), and when RCS was released, my partner—who uses a Samsung—started sending me messages via RCS. On my iPhone, everything works perfectly: I receive both RCS and SMS messages in a single conversation thread.

However, on my MacBook Pro, things get messy. When I send her a message via iMessage, it sometimes goes out as RCS (or SMS). Then, when she replies, the iMessage app on my Mac creates a new conversation with the same person. As a result, my original conversation thread on the Mac stops receiving her replies.

Both my iPhone and MacBook Pro are updated to the latest stable OS versions and are not on Beta. Despite this, the issue persists.

Essentially, I end up with two conversations for the same person—one where I send messages and another where I receive her replies. It’s very confusing and inconvenient.