When a message arrives, it appears on both the Apple Watch Series 3 GPS only (OS 4.3) and the iPhone-7 (IOS-11.3). So far, so good.
However, if I delete the message on EITHER device, it remains on the other device. I have to delete from both devices separately. This occurs with incoming messages, outgoing messages, txt messages and iMessages.
Is there something that I can do about this?
iMac (Retina 4K, 21.5-inch, 2017), macOS High Sierra (10.13.2)