Achtung @tbg 
I update my system several times a day.
Until yesterday all was fine.
Today I updated again and… I cannot sleep/standy anymore! 
Does this help understanding what the root of the problem is?
Here’s my inxi again, for reference:
System:
Kernel: 6.8.4-zen1-1-zen arch: x86_64 bits: 64 compiler: gcc v: 13.2.1
clocksource: tsc avail: hpet,acpi_pm
parameters: BOOT_IMAGE=/@/boot/vmlinuz-linux-zen
root=UUID=1930b164-e875-487b-9e15-d08dfb606021 rw rootflags=subvol=@
quiet quiet rd.udev.log_priority=3 vt.global_cursor_default=0 loglevel=3
ibt=off resume=UUID=290da5e7-6510-4b46-9fa1-14463cba09cf
Desktop: KDE Plasma v: 6.0.3 tk: Qt v: N/A info: frameworks v: 6.0.0
wm: kwin_x11 vt: 2 dm: SDDM Distro: Arch Linux
Machine:
Type: Desktop Mobo: ASRock model: P67 Extreme4 serial: <superuser required>
uuid: <superuser required> BIOS: American Megatrends v: P3.10
date: 04/24/2012
Battery:
Device-1: hidpp_battery_0 model: Logitech G604 Wireless Gaming Mouse
serial: <filter> charge: 100% (should be ignored) rechargeable: yes
status: discharging
CPU:
Info: model: Intel Core i5-2500K bits: 64 type: MCP arch: Sandy Bridge
gen: core 2 level: v2 built: 2010-12 process: Intel 32nm family: 6
model-id: 0x2A (42) stepping: 7 microcode: 0x2F
Topology: cpus: 1x cores: 4 smt: <unsupported> cache: L1: 256 KiB
desc: d-4x32 KiB; i-4x32 KiB L2: 1024 KiB desc: 4x256 KiB L3: 6 MiB
desc: 1x6 MiB
Speed (MHz): avg: 1614 high: 1667 min/max: 1600/5900 scaling:
driver: intel_cpufreq governor: schedutil cores: 1: 1667 2: 1600 3: 1596
4: 1596 bogomips: 26341
Flags: avx ht lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx
Vulnerabilities: <filter>
Graphics:
Device-1: NVIDIA GM204 [GeForce GTX 970] vendor: ZOTAC driver: nvidia
v: 550.67 alternate: nouveau,nvidia_drm non-free: 545.xx+ status: current
(as of 2024-02; EOL~2026-12-xx) arch: Maxwell code: GMxxx
process: TSMC 28nm built: 2014-2019 pcie: gen: 2 speed: 5 GT/s lanes: 16
ports: active: none off: DP-1,DVI-I-1 empty: DVI-D-1,HDMI-A-1
bus-ID: 01:00.0 chip-ID: 10de:13c2 class-ID: 0300
Display: x11 server: X.Org v: 21.1.12 with: Xwayland v: 23.2.5
compositor: kwin_x11 driver: X: loaded: nvidia unloaded: modesetting
alternate: fbdev,nouveau,nv,vesa gpu: nvidia,nvidia-nvswitch
display-ID: :0 screens: 1
Screen-1: 0 s-res: 1920x1080 s-dpi: 97 s-size: 503x283mm (19.80x11.14")
s-diag: 577mm (22.72")
Monitor-1: DP-1 note: disabled model: Panasonic Panasonic-TV
serial: <filter> built: 2010 res: N/A gamma: 1.2
size: 698x392mm (27.48x15.43") modes: max: 1920x1080 min: 640x480
Monitor-2: DVI-I-1 note: disabled pos: primary model: LG (GoldStar) W2363D
serial: <filter> built: 2011 res: 1920x1080 dpi: 96 gamma: 1.2
size: 510x287mm (20.08x11.3") diag: 582mm (22.9") ratio: 16:9 modes:
max: 1920x1080 min: 640x480
API: EGL v: 1.5 hw: drv: nvidia platforms: device: 0 drv: nvidia device: 2
drv: swrast gbm: drv: nvidia surfaceless: drv: nvidia x11: drv: nvidia
inactive: wayland,device-1
API: OpenGL v: 4.6.0 compat-v: 4.5 vendor: nvidia mesa v: 550.67
glx-v: 1.4 direct-render: yes renderer: NVIDIA GeForce GTX 970/PCIe/SSE2
memory: 3.91 GiB
API: Vulkan v: 1.3.279 layers: 5 device: 0 type: discrete-gpu
name: NVIDIA GeForce GTX 970 driver: nvidia v: 550.67 device-ID: 10de:13c2
surfaces: xcb,xlib device: 1 type: cpu name: llvmpipe (LLVM 17.0.6 256
bits) driver: mesa llvmpipe v: 24.0.4-arch1.2 (LLVM 17.0.6)
device-ID: 10005:0000 surfaces: xcb,xlib
Audio:
Device-1: Intel 6 Series/C200 Series Family High Definition Audio
vendor: ASRock 6 driver: snd_hda_intel v: kernel bus-ID: 00:1b.0
chip-ID: 8086:1c20 class-ID: 0403
Device-2: NVIDIA GM204 High Definition Audio vendor: ZOTAC
driver: snd_hda_intel v: kernel pcie: gen: 2 speed: 5 GT/s lanes: 16
bus-ID: 01:00.1 chip-ID: 10de:0fbb class-ID: 0403
Device-3: Logitech G430 Surround Sound Gaming Headset
driver: hid-generic,snd-usb-audio,usbhid type: USB rev: 1.1 speed: 12 Mb/s
lanes: 1 mode: 1.1 bus-ID: 1-1.2:4 chip-ID: 046d:0a4d class-ID: 0300
Device-4: M-Audio AIR 192 6 driver: snd-usb-audio type: USB rev: 2.0
speed: 480 Mb/s lanes: 1 mode: 2.0 bus-ID: 2-1.5:3 chip-ID: 0763:410c
class-ID: fe01
API: ALSA v: k6.8.4-zen1-1-zen status: kernel-api with: aoss
type: oss-emulator tools: N/A
Server-1: PipeWire v: 1.0.4 status: active with: 1: pipewire-pulse
status: active 2: wireplumber status: active 3: pipewire-alsa type: plugin
4: pw-jack type: plugin tools: pactl,pw-cat,pw-cli,wpctl
Network:
Device-1: Realtek RTL8111/8168/8211/8411 PCI Express Gigabit Ethernet
vendor: ASRock driver: r8169 v: kernel pcie: gen: 1 speed: 2.5 GT/s lanes: 1
port: b000 bus-ID: 0c:00.0 chip-ID: 10ec:8168 class-ID: 0200
IF: enp12s0 state: up speed: 1000 Mbps duplex: full mac: <filter>
Device-2: Realtek RTL88x2bu [AC1200 Techkey] driver: rtw_8822bu type: USB
rev: 2.1 speed: 480 Mb/s lanes: 1 mode: 2.0 bus-ID: 2-1.6:4
chip-ID: 0bda:b812 class-ID: 0000 serial: <filter>
IF: wlp0s26u1u6 state: up mac: <filter>
Info: services: NetworkManager, systemd-timesyncd, wpa_supplicant
Bluetooth:
Device-1: Cambridge Silicon Radio Bluetooth Dongle (HCI mode) driver: btusb
v: 0.8 type: USB rev: 2.0 speed: 12 Mb/s lanes: 1 mode: 1.1 bus-ID: 1-1.3:5
chip-ID: 0a12:0001 class-ID: e001
Report: btmgmt ID: hci0 rfk-id: 0 state: up address: <filter> bt-v: 4.0
lmp-v: 6 status: discoverable: no pairing: no class-ID: 6c0104
Drives:
Local Storage: total: 2.85 TiB used: 216.55 GiB (7.4%)
SMART Message: Unable to run smartctl. Root privileges required.
ID-1: /dev/sda maj-min: 8:0 vendor: Samsung model: SSD 860 EVO 1TB
size: 931.51 GiB block-size: physical: 512 B logical: 512 B speed: 6.0 Gb/s
tech: SSD serial: <filter> fw-rev: 3B6Q scheme: MBR
ID-2: /dev/sdb maj-min: 8:16 vendor: Seagate model: ST2000DX001-1NS164
size: 1.82 TiB block-size: physical: 4096 B logical: 512 B speed: 6.0 Gb/s
tech: HDD rpm: 7200 serial: <filter> fw-rev: CC41 scheme: MBR
ID-3: /dev/sdc maj-min: 8:32 vendor: Crucial model: M4-CT128M4SSD2
size: 119.24 GiB block-size: physical: 512 B logical: 512 B speed: 6.0 Gb/s
tech: SSD serial: <filter> fw-rev: 070H scheme: MBR
Partition:
ID-1: / raw-size: 50 GiB size: 46.57 GiB (93.13%) used: 42.7 GiB (91.7%)
fs: btrfs dev: /dev/sda2 maj-min: 8:2
ID-2: /home raw-size: 414.91 GiB size: 414.91 GiB (100.00%)
used: 173.85 GiB (41.9%) fs: btrfs dev: /dev/sda3 maj-min: 8:3
ID-3: /var/log raw-size: 50 GiB size: 46.57 GiB (93.13%)
used: 42.7 GiB (91.7%) fs: btrfs dev: /dev/sda2 maj-min: 8:2
ID-4: /var/tmp raw-size: 50 GiB size: 46.57 GiB (93.13%)
used: 42.7 GiB (91.7%) fs: btrfs dev: /dev/sda2 maj-min: 8:2
Swap:
Kernel: swappiness: 133 (default 60) cache-pressure: 100 (default) zswap: no
ID-1: swap-1 type: zram size: 15.58 GiB used: 0 KiB (0.0%) priority: 100
comp: zstd avail: lzo,lzo-rle,lz4,lz4hc,842 max-streams: 4 dev: /dev/zram0
ID-2: swap-2 type: partition size: 16.6 GiB used: 0 KiB (0.0%)
priority: -2 dev: /dev/sda4 maj-min: 8:4
Sensors:
System Temperatures: cpu: 36.0 C mobo: N/A gpu: nvidia temp: 34 C
Fan Speeds (rpm): N/A gpu: nvidia fan: 32%
Info:
Memory: total: 16 GiB available: 15.58 GiB used: 4.45 GiB (28.6%)
Processes: 272 Power: uptime: 2m states: freeze,standby,mem,disk
suspend: deep avail: s2idle,shallow wakeups: 0 hibernate: platform
avail: shutdown, reboot, suspend, test_resume image: 6.17 GiB
services: org_kde_powerdevil, power-profiles-daemon, upowerd Init: systemd
v: 255 default: graphical tool: systemctl
Packages: pm: pacman pkgs: 1702 libs: 515 tools: octopi,paru Compilers:
clang: 17.0.6 gcc: 13.2.1 Shell: garuda-inxi default: Bash v: 5.2.26
running-in: konsole inxi: 3.3.33
Garuda (2.6.24-1):
System install date: 2024-01-27
Last full system update: 2024-04-07
Is partially upgraded: No
Relevant software: snapper NetworkManager dracut nvidia-dkms
Windows dual boot: <superuser required>
Failed units:
Happiness lasted three days, lol.
Thanks again!
EDIT: I managed to sleep once, for mysterious reasons, but the other 4/5 tries all failed.