Okay, searching for “systemd-sleep User sessions remain unfrozen” gave me:
- https://forum.manjaro.org/t/systemd-256-may-break-sleep/167722/9
- Gentoo Forums :: View topic - [~SOLVED] systemd 256 breaks resume from suspend w/ NVIDIA
- [SOLVED] problem with systemd hibernate / Newbie Corner / Arch Linux Forums
Does one of these help you?