I had the same issues. Mine shut down after a while, as it was flushing changes to disk. Mine never went to sleep with raid setup, fans stayed on and everything.
Never solved any of it, and I actually disabled raid since it was such a pain in the backside. In terms of data security, you would be better off to keep one drive disconnected, and backup data to it on a regular basis. That way it has much less chance of being hit by ransomware.
I think you need to disable win10 fast startup and compatibility support module in bios, but don't quote me on that, I have never tried it personally, as I abandoned RAID fairly quickly. I will likely try it again after my exams are over.