I'm running Win 10 64bit on Ryzen 7 1700 and Vega 64 using two monitor, primary is a 4K, extended is a 1080P.
When I'm running HF Pro 2017 and when both screen standby HF crash. This happened three times in row, so I switched back to a singular monitor and didn't happened again. HF was only on primary monitor.
I can perform some test if you want and give you as much info as possible.