Experiencing similar artifact issues using the contour tool in the latest release of AD (126.96.36.1999). I didn't want to create a duplicate thread, so posting here. This happens with OpenCL disabled as well as enabled. Please see the attached video.
Hardware specs: AMD Ryzen 4800h with RTX 2060 (laptop) running Windows 10 20H2. All drivers updated to the latest (Nvidia studio).
PS: I'm also seeing high CPU usage with this release (sudden spikes up to 90-100%), which wasn't the case with the 1.8.x versions. This pushes the CPU temps dangerously close to the 100 degree Celsius mark. The GPU usage remains very low, however, barely exceeding 50% in a stressful document. I know vector programs are CPU-heavy but wasn't the 1.9 version promising full HW acceleration support with the new Nvidia drivers?