Some users have recently had their accounts hijacked. It seems that the now defunct EVGA forums might have compromised your password there and seems many are using the same PW here. We would suggest you UPDATE YOUR PASSWORD and TURN ON 2FA for your account here to further secure it. None of the compromised accounts had 2FA turned on.
Once you have enabled 2FA, your account will be updated soon to show a badge, letting other members know that you use 2FA to protect your account. This should be beneficial for everyone that uses FSFT.
I tried just doing a shutdown and had exactly the same problem. If I had a spare PSU it would be easy to prove what the problem is of course - it's going to be either motherboard or PSU. I just don't fancy having to buy another PSU just to prove a point!
I have EXACTLY this problem with the "wake up" not working. Have been tearing my hair out and also suspect it's something to do with sleep mode. Did you ever work out a final solution or was the PSU the main issue? I also have a Seasonic as well.
I have a self-built PC with the Asus Z87 Pro, which had been working fine since it was built. This weekend though, for the first time, the PC was in sleep mode for 48 hours (normally it's in use every day). Pressing the power button did nothing. The PC appeared dead. I checked the motherboard...