Bluetooth connectivity on iPhone X keeps dropping

I keep on having to pair up my iPhone X to messages on my iMac as the Bluetooth network connection continually drops... never happened with my old iPhone. When I click on Bluetooth in the menu bar and the window shows the connect to iPhone option nothing happens when I select it. So I select open Bluetooth preferences and then choose 'connect to network nothing happens either. I can only make the connection active through my iPhone,,,, but this drops after a few minutes. This has essentially rendered the messages app on my iMac useless.

Any ideas?