New TacX NEO 2T Trainer not consistently working with Garmin Fenix 6x Pro or TacX App or Zwift.

I am using a brand new TacX NEO 2T Trainer. I set it up a week or so ago, followed all the instructions, but I cannot get it to consistently work with my Garmin Fenix 6x Pro watch or even the TacX app or Zwift.  At times, for example, I can control the Resistance and Grade on my watch, and then at others, even though my watch shows the Resistance or Grade is increased, nothing happens with the resistance on the Trainer.  Also, it shows by speed way higher than it should.  I typically maintained about 16 to 17 MPH on my old mechanical Kurt Kinetic trainer, but the Tacx says I am regularly going 30 MPH+!  I have tried to find descriptive manuals on line, but the only things that come up are these forums and the very basic setup "manual" that came with the trainer.  Getting ready to send this one back and either get a Wahoo or go back to my Kurt Kinetic.  Any thoughts on why I am having the above issues?  Many thanks!