I have Vector 3 Pedals (dual sensors) and also get similar issue especially when warming up or at lower wattage.
Power drops to half. After pedaling for a bit (sometimes can take 2-5mins) it will eventually pop back up to full power. But i still get drop-downs to 50% power while riding sporadically for a few seconds.
Recently I’m also getting power spikes to 2,000+ watts when i step onto the bike. It’s unlocked a ton of zwift things inadvertently but super annoying as when i got back to look at all my graphs, they’re scaled up to 2,000 Watts and the rest of the logs are small.
It’s also not a Zwift issue. I logged the same workout on my Garmin Fenix 5s and was getting the same 50% drop as i saw in Zwift. So the data coming out of the peodals is wrong.
outside of this issue though, i really love the pedals so I hope that the issue either subsides on it’s own or enough of us come out and Garmin can look into core issue. When they’re working well, they power is almost right on top of my Kurt Kinetic In-Ride Power Meter.