I too was having similar problems with 2.0 which didn't occur on 1.56 and eventually realised it was heat related.
My particular 1080 required a bios upgrade as the fan speed was designed to be slower to keep it quieter!
However, the biggest difference was me taking a vacuum cleaner to the cpu liquid cooler. I removed the fan and the radiator was 'caked' in fluff and dust.
It seems 2.0 requires a lot more work from the cpu to be done to work properly, whereas 1.56 doesn't.