Reboot during sleep

I put my hackintosh to sleep at night, only to find the Clover bootloader the next morning.

I can't find anything interesting in the logs (keywords: crash, panic, reboot, restart)

I do get something with > pmset -g log | grep -i failure:

2017-07-10 15:31:05 +0200 Failure Notification Failure during wake due to 0xA34068004000024:

2017-07-13 18:28:51 +0200 Failure Notification Failure during wake due to 0x634025604000024:

2017-07-14 11:31:47 +0200 Failure Notification Failure during wake due to 0x734025604000024:

2017-07-15 10:03:46 +0200 Failure Notification Failure during wake due to 0x2340DBE04000024:

2017-07-15 21:02:51 +0200 Failure Notification Failure during wake due to 0x734005004000024:

2017-07-19 20:12:51 +0200 Failure Notification Failure during wake due to 0xB340E4004000024:

2017-07-24 18:03:18 +0200 Failure Notification Failure during wake due to 0x73400B404000024:

With all these notifications I get the same message:

Kernel Idle sleep preventers: IODisplayWrangler

However, judging by the time, these don't appear to be overnight crashes.

I know a lot of people get crashes on wake from sleep, but in my case I can wake from sleep just fine. At least when I try manually.

Full specs Asus H97M-E i7-4970s GTX 970

Clover configuration