How accurate are consumer smart radon detectors compared to professional tests?

Across the radon-focused communities we read, consensus is that the better consumer monitors (Ecosense RadonEye/EcoQube, Airthings Corentium/View, Aranet Radon Plus) track within roughly 10-20% of professional continuous radon monitors once given enough time to average. Short-term readings in the first 24 hours are noisy on every device; long-term averages are what matter for mitigation decisions.