Here is the forum where I got the info about the S3 sleep state: bbs.archlinux.org/viewtopic.php?id=291345. It talks a little about NVIDIA, but obviously that won’t help you.
You could also play around with powrcfg in Windows to see if here are errors. That’s all I got as I don’t know how to tinker with APM/ACPI in Linux.
Quite frankly, when I have had sleep issues in the past, I just disabled it since power management can be extremely problematic in a lot of instances. (This might be related in some way: community.amd.com/t5/graphics-cards/…/576586)