I use the 'Ride a Course' function on my Fenix 6 Pro Solar to vary cycle training. I create a course, either in Komoot or Garmin Connect, send it to the watch, connect the watch to the trainer and ride. I'm using a Saris M2, and it has worked fine since I bought it in January - II'd get varying resistance in the trainer to match the terrain, and in the end the ride recorded with the correct elevation gains and so on.
Now, however the elevation does not record at all, and sometimes the elevation data while riding looks crazy. For example last time I tried it the elevation plot was correct on the watch before I started but once I started riding the elevation plot showed I was starting 500 m below sea level and was due to climb to several million metres.
The elevation gain for 'real activities' is still correct and still being recorded. It's just the virtual activities that have stopped working.
Any advice much appreciated. Thanks.