How do I send my training calendar to my Fenix 6?

It's automatic now.  Just add the workouts to the calendar then sync the watch. 

If it matters it only syncs 30 days ahead now. 

I am following a cycling workout plan and for whatever reason, most days show up only on my Edge 530, not on the Fenix 6.  Super odd though, some of the workouts do show up on the Fenix 6 calendar.  I'm not sure what the reasons are though, so I can't really help but I share your pain.

Sorry, don't have an answer there. :(   Using GCM I can add a workout to the calendar or schedule them in the browser in connect and either way it just shows up on my watch.  I don't have to do anything other than schedule it. 

When you look at your calendar on your phone you see the scheduled workouts?   If they're not showing there that would likely be the cause, why they're not showing I can't say, never seen that before either unfortunately. 

Note I'm using an Android phone but my running partner uses an Apple device and it works the same way on hers. 

Hello. I solved the problem... kind of unorthodox, but I solved it. The only way to send my training calendar to my F6 was to remove the device from my Garmin account and then to add it again... after adding it al calendar was sincronised with watch. It is not normal way, but it is a way to solve the problem.

what brand phone do you have ? Maybe it's a phone issue...If you sync with Garmin Express does it works better without connec/disconnect Fenix from GC app ?