Does anyone else have a problem where miner just shuts down, no error no nothing, just closes ?
Yes I get that from time to time on Windows 10 ... it's down to overclocking usually. I lower core and memory clocks by 5 and restart. If the problem doesn't repeat itself then I have a stable rig, otherwise I lower again until it is.
Sometimes I'll increase the TDP as well.
... it's all about tuning your rig for the best watt/hash performance.