I am using NixOS Unstable with all the latest kernel and BIOS updates.
I moved from 24.05 which had the same problems. What is wrong is that all OS based deep sleep/full power off, anything S4 and higher, does not work.
To get the device in this state I have to use the OS power off then after waiting for a long time to make sure it is done I have to hold down the power button for 5 seconds for the force shutdown mode built into all computers.
I have tried reading related posts in the forum and I have tried about 10 different sets of kernel parameters to no change.
Tomorrow I am getting a second SSD for Windows so that will let me test if it is a BIOS/Hardware problem or a software problem.
I cant check the acpi settings on the BIOS because Framework decided that was not important enough to make the cut even on the advanced tab of the BIOS so I dont know if this is a BIOS problem.
It is very late where I am so it might take me a minute to respond. In the morning I will take another crack at it and I will post my full NixOS config, it is a pretty basic config as I just got the laptop and have been working on this power state thing for a while now.
For some reason S1-S2 works perfectly and S3 is just non existent.