Arch Linux - Monitors will never go to sleep

Through searching I can only find people looking to solve the opposite issue. I am running Arch Linux with i3 as my window manager. I am using i3-lock to handle screen locking. I can lock the screen, however the monitors never go to sleep, and will stay on in perpetuity displaying the i3-lock blank screen. Here is the [relevant] output of xset q:

DPMS (Display Power Management Signaling):
  Standby: 300    Suspend: 300    Off: 1800
  DPMS is Enabled
  Monitor is On

Here is the part of my i3config where I declare my dpms settings:

exec --no-startup-id xset dpms 300 300 1800
 exec --no-startup-id xss-lock --transfer-sleep-lock -- i3lock --nofork

I am using an AMD 6950XT, here is the (relevant) output of lspci -v:

01:00.0 PCI bridge: Advanced Micro Devices, Inc. [AMD/ATI] Navi 10 XL Upstream Port of PCI Express Switch (rev c0) (prog-if 00 [Normal decode])
	Flags: bus master, fast devsel, latency 0, IRQ 16
	Memory at b0600000 (32-bit, non-prefetchable) [size=16K]
	Bus: primary=01, secondary=02, subordinate=03, sec-latency=0
	I/O behind bridge: 4000-4fff [size=4K] [16-bit]
	Memory behind bridge: b0300000-b05fffff [size=3M] [32-bit]
	Prefetchable memory behind bridge: a0000000-b01fffff [size=258M] [32-bit]
	Capabilities: 
	Kernel driver in use: pcieport

02:00.0 PCI bridge: Advanced Micro Devices, Inc. [AMD/ATI] Navi 10 XL Downstream Port of PCI Express Switch (prog-if 00 [Normal decode])
	Subsystem: Advanced Micro Devices, Inc. [AMD/ATI] Navi 10 XL Downstream Port of PCI Express Switch
	Flags: bus master, fast devsel, latency 0, IRQ 125
	Bus: primary=02, secondary=03, subordinate=03, sec-latency=0
	I/O behind bridge: 4000-4fff [size=4K] [16-bit]
	Memory behind bridge: b0300000-b05fffff [size=3M] [32-bit]
	Prefetchable memory behind bridge: a0000000-b01fffff [size=258M] [32-bit]
	Capabilities: 
	Kernel driver in use: pcieport

03:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Navi 21 [Radeon RX 6950 XT] (rev c0) (prog-if 00 [VGA controller])
	Subsystem: Advanced Micro Devices, Inc. [AMD/ATI] Navi 21 [Radeon RX 6950 XT]
	Flags: bus master, fast devsel, latency 0, IRQ 179
	Memory at a0000000 (64-bit, prefetchable) [size=256M]
	Memory at b0000000 (64-bit, prefetchable) [size=2M]
	I/O ports at 4000 [size=256]
	Memory at b0400000 (32-bit, non-prefetchable) [size=1M]
	Expansion ROM at b0500000 [disabled] [size=128K]
	Capabilities: 
	Kernel driver in use: amdgpu
	Kernel modules: amdgpu

03:00.1 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] Navi 21/23 HDMI/DP Audio Controller
	Subsystem: Advanced Micro Devices, Inc. [AMD/ATI] Navi 21/23 HDMI/DP Audio Controller
	Flags: bus master, fast devsel, latency 0, IRQ 199
	Memory at b0524000 (32-bit, non-prefetchable) [size=16K]
	Capabilities: 
	Kernel driver in use: snd_hda_intel
	Kernel modules: snd_hda_intel

03:00.2 USB controller: Advanced Micro Devices, Inc. [AMD/ATI] Device 73a6 (prog-if 30 [XHCI])
	Subsystem: Advanced Micro Devices, Inc. [AMD/ATI] Device 73a6
	Flags: bus master, fast devsel, latency 0, IRQ 18
	Memory at b0300000 (64-bit, non-prefetchable) [size=1M]
	Capabilities: 
	Kernel driver in use: xhci_hcd
	Kernel modules: xhci_pci

03:00.3 Serial bus controller: Advanced Micro Devices, Inc. [AMD/ATI] Navi 21 USB
	Subsystem: Advanced Micro Devices, Inc. [AMD/ATI] Navi 21 USB
	Flags: bus master, fast devsel, latency 0, IRQ 127
	Memory at b0520000 (64-bit, non-prefetchable) [size=16K]
	Capabilities: 
	Kernel driver in use: i2c-designware-pci

How can I get my monitors to actually follow the DPMS settings? The monitors stay on 24/7, and I usually end up having to power them off and on, which is annoying.