What’s changed with the Garmin measurements?

Most of my KPIs have all dropped or degraded difficult. For the exact same work out (Outdoor ride, same distance, same ascent, etc., Garmin is tracking lower aerobic number, no anaerobic, 30% fewer calories burned, which has produced a lower VO2 MAX and a higher fitness age. Nothing on my side has changed. Has Garmin changed its algorithm or something else?? Is anyone else reporting the same experience? Please advise.