Elevation Discrepancy on London and Richmond

I’ve noticed on several London courses and the Richmond UCI course the elevation isn’t adding up to what the Zwift total elevation gain should be. On UCI I believe the gain should be around 520 feet and every time I ride I end up closer to 420 feet. While riding on both London and Richmond I’ve noticed the elevation gain is not adding in 1 foot increments but 6-7 feet at a time. I feel like on small hills where there is less than 5-6 feet of elevation gain, Zwift is not adding that amount to the elevation totals.

I’m having this same issue. I’ve actually stopped riding Londons courses because the elevation is always so off and I lost probably 200’ of elevation on my rounds on the UCI World’s Course yesterday.