Did you mix up S0, S0ix, and S3? S0 is running, S3 is traditional standby (the one you want?), S0ix is modern standby (the one that gave you trouble).
Microsoft's Fast Startup is also known as Hybrid Shutdown. When Modern Standby is enabled, a system shutdown will log the user off, then use a combination of S4 Hibernation and S0 Standby.
https://learn.microsoft.com/en-us/windows/win32/power/system...