The following solution, or workaround, works for me (found on <https://bbs.archlinux.org/viewtopic.php?id=296954>). I made a file /etc/systemd/system/systemd-suspend.service.d/override.conf containing these two lines:
[Service] Environment="SYSTEMD_SLEEP_FREEZE_USER_SESSIONS=false" (I did so via "systemctl edit systemd-suspend.service") Now suspend works reliably. Apparently this new behavior, of freezing the user slice, was introduced in systemd 256, so I must have been running an earlier version for a while. Anyway, now I am running systemd 260~rc4-1 (kernel 6.19.6+deb14-amd64). This solution was proposed first to solve suspend problems with properietary NVIDIA drivers. However, I had similar suspend problems without any proprietary drivers (the laptop uses intel graphics), and the same solution worked for me as for the NVIDIA users. -Sanjoy P.S. A few sites describe the new configuration slightly incorrectly and give the magic line simply as SYSTEMD_SLEEP_FREEZE_USER_SESSIONS=false
