Crazy sleep issue (pun intended)

Damn this Hackintosh sleep issue causing me sleepless nights. Everything in my OC 0.6.1 Hackintosh build works perfectly except the sleep. So far the characteristics of my issue are

1. If I'm putting my computer in sleep for the first time after a fresh boot, sleep works normally (80% of the time I have tried). Computer goes to sleep, and keep sleeping until I wake it up manually. So no issues.
2. Other 20% of the time, computer goes to sleep normally, but restarts when I wake it from sleep.
3. If step 1 worked, then the next time when I put my computer into sleep, it restarts immediately (happens 100% of the time). Even before going to sleep.

I checked the console logs around the time of reboot, but couldn't find anything related to reboot. May be I'm not looking at the right place or looking for the right thing. Any help to find the cause of this issue by checking logs would be much appreciated. I have all my USB ports mapped and working fine. I checked almost everything mentioned in Dortania OC guide related to fix sleep issues but no luck.

I have another issue as well which is (I believe) not related to this sleep issue. Sometimes (completely randomly) My hack reboots while booting Mac OS. It happens few minutes after selecting Mac OS from OC boot menu. ie I can see scrolling logs for some time, then machine restarts abruptly. Sometimes I have try 3 or 4 times to get into login screen since it will keep rebooting. I compared OC logs of normal boot with this abrupt reboot (both will generate logs in OC) and found they are exactly the same except the time stamps. This issue also bugs me and I couldn't find any solution so far.

My Hack spec is: i7 9700K, Gigabyte z390i aorus pro, RX 5700xt.