Garmin support says to disable individual segments on your device. Well, new segments show up still, and things get re-enabled. When Segments are enabled, it chews up more battery, just like following a course. Also, Garmin support takes DAYS to respond, and seems to send you to a level zero support queue first.
Strava support was awesome. I got a simple, exact response in three hours. To disable live segments, go to garmin connect. From the hamburger menu in the top left, click the arrow next to segments (way down in the list). Click the button to add it to your dashboard. Now, you’ll see the widget on your dashboard. From there, click the gear on the widget. Choose “Use Garmin Segments”. BLAM! You’re back to not using Strava Live Segments. You can toggle it on and off there, even though the initial enablement is on Strava’s webpage.
I wanted this disabled, because every time I would go near a segment, it would beep at me a few times. If I crossed over the start of a segment, it would beep no less than 15 times before it gave up. This is from an Edge 520 on version 7 code. Maybe it’ll be better in the future, but it’s just a distraction to me. YMMV