No Comms between Easel and Adruino

Thanks to some hints on another thread, I’m at a new problem perhaps someone can recognize.

I have a DIY mini engraver. I can export Gcode from Easel>WordPad>GrblController . It works and the mill moves as it should (I have no tool in the collet for this test).

However, if I try to connect (using the MACHINE tab in Easel) Easel>Arduino/Gshield nothing happens. I’ve tried rebooting…nada. However without touching anything in the hardware setup, I can go back into GrblController and immediately re-establish communications.

I’m selecting XCarve in the machine type, though it seems like it should matter

Thanks for any help.