I've been using Strava Live Segments on my Fenix 5S since the beginning (starting at version 5.xx) and had no issues with it for a long time, even with FW. 7.00 it worked like a charm. If my memory serves me well, the issue I'm going to describe started with FW 7.60 and persists now with FW 8.00...
The issue is that after a while the watch is no longer giving notice when approaching a Strava Live Segment and basically the functionality to race a segment doesn't start. I check the watch after the run via Run Activity Settings > Training > Strava Live Segments and the segments are all there! Nevertheless they don't work.
Here's a "solution" I found, but it only works temporarily so that doesn't make me happy:
1. I go to Garmin Connect (online), to the Dashboard, Segments widget, and switch from Strava to Garmin segments, and synchronize.
2. I check the watch, all segments are gone.
3. Then, I go back to Garmin Connect (online), to the Dashboard, Segments widget, and switch back to Strava Live segments, and synchronize again
4. I check the watch, all segments are back.
Now Strava Live Segments work again... at least for a while. After a few synchronizations, the problem is back and I can start all over.
Anyone seen this? Is there a better / more permanent solution?