It would require someone testing with affected hardware and the latest 384.59 driver (which you can find in these LE9/Kodi 18 test builds) to know for sure.
There is one mention of a suspend bug fix in 384.59 but it only applies to SLI so is unlikely to be responsible for the issues reported in this thread, but you never know what else might have been fixed...
384.59 will be in the next LibreELEC 8 official release (once Kodi 17.4 is released).
I'm on the latest LE9 test build with an ASUS GTX750TI.
With LE8 I recognized a suspend issue for the first time and I was able to work around by forcing the legacy driver. The issue is that if I enter suspend, the machine doesn't go sleep entirely - it hang up in an somehow undefined state with black screen and therefor afterwards no chance to wake it up again. Maybe that's not the exact same behavior but at least it sounds like the same family of issues.
By the latest LE9 build it is still not solved - I think the mentioned 384.59 Nvidia drivers are active by default and I do not need to activate them somehow first?!
The issue is gone again after I force the legacy driver.