I hope this isn't too redundant of a question, but this happened on my last run.
I created a Course on Garmin Connect. The trail I wanted to run wasn't on the Google layer, but it was on OSM. I used OSM to create the track and then switched to Google maps before saving it. The route is about 17 miles but all on the same trail. I then loaded it onto my watch via Garmin Connect. When I went to do the course I got the error '50 course point max exceeded. Final 51 points will not be shown'. The Map and the Elevation profile all looked correct. There were a lot of un-needed TBT alerts and about half way through the run the TBT alerts just stopped.
For comparison, I have a 15-ish mile trail run that this doesn't happen on.
What happens when the course points are maxed out?
I didn't see any way to control this in Garmin Connect. How or can this be controlled?