Using this on my iMac 2013 with GeForce GTX 780M running Catalina worked: https://www.nvidia.com/en-us/drivers/cuda/418_163/macosx-cuda-418_163-driver/ Sad news to report, I'm getting glitches again, fewer than before. I don't know if it's because reboots helped, or if there are fewer bugs in the d...