I replaced my Edge 820 with a new 830 back in June and since then I haven’t got a single VO2 max update, I ride with vector 3 power meters and garmin HRM band. With the 820 I used to get regular VO2 max updates but now even after 1400km ridden I still don’t get it. One detail that could’ve influenced it is the fact that at the same time I started using the edge 830 I also started using a vivoactive 3 watch. The watch seems to be able to calculate vo2 max on my walks for example.