In case this is related to your issue, please see the following information mentioned in Stable Update 2024-09-02:
A feature in systemd 256 freezing a user session when suspending may freeze the system.
- Power management/Suspend and hibernate (ArchWiki)
- [SOLVED] System freezes after sleep since update (Arch Linux Forums)
- Systemd 256 may break sleep
The issue is most prominent with Nvidia systems but reports exist that it may affect other systems as well.
A workaround for this is to create an override configuration file;
/etc/systemd/system/systemd-suspend.service.d/disable_freeze_user_session.conf
If you are confident that this is not related, ignore this post.
Cheers.