I have an asrock motherboard which doesn’t like losing power (z97, so a little older than this one). Usually, I have to press the reset and CLRCBTN1 buttons on the motherboard, flip the switch on the PSU, wait 15 minutes, turn the PSU back on, try turning it on using the power button on the motorboard, maybe spam the reset/clrcbtn1 button some more and hope it works. Sometimes I can skip the PSU part, but not often. Think my model motherboard has some manufacturing defect related to the CMOS, because others have reported similar issues.