This has been reported before. But, it remains a problem.
I mostly bike as my cardio exercsie. I got the Edge 850 and was excited to see the new features. In general, I love being able to follow my Cycling Coach trainings on the Edge. I like the voice prompts and the graphic displays.
I also have a Forerunner 965 and an HRM 600. But, the Garmin Coach Plans are not getting sync'ed on the Edge.
I previous tried to make the Edge 850 my Primary Training Device. That was a big mess. I was getting 3 completely different suggestions between the Forerunner, the Connect App, and the Edge. So, I changed my Primary Training Device back to my Forerunner.
Now, at least the Forerunner and the Connect app are sync'ed up with respect to the Coach suggestions. But, the Edge is frequently out of sync.
If the Edge is correct, I use it and love it. If it is not, I do the training with my Forerunner and the Edge in Extended Display Mode. But, that is not as good. It does not provide the great feedback that the Edge would provide.