connectable false ble issues

Okay so I think its actually :
connectable:false from setAdvertising options
Which makes it do this, is that expected behaviour? I'm not 100% sure what it does. Shouldn't Make Connectable restore this to true anywaY?

Here is my code :

(function() {
	g.setBgColor(0b000000111111000000);
	g.clear(false);

	NRF.setAdvertising({},{
      connectable:false,
    });
})();

Steps to reproduce :
send to ram the above code.
Disconnect.
Wait for advertising to resume after disconnecting. Bangle appears in List.
Try to connect again with ide to bangle.
Error : Connection Failed in red.
Now all advertising has stopped on bangle.js suddenly. And can't turn it back on, unless Turn Off in settings.