Really? There's no way I'm that quick. I'll investigate, and do a bit more testing to see that I'm recording this all correctly.
As you are reasonably light at 73kg and near the bottom end of a category you'll need to hone your Zwift racing skills! It'll be tough as you'll be racing against people who are 80+ kg and near 4 w/kg so FTP of 320+ watts which is a lot more power than you. So you'll find it hard on the flats unless you're good at hiding as others will have a lot more power (probably near threshold just to stay in their draft.) And you'll find it hard on the hills as you're at the bottom end of w/kg scale. Good luck