Xrandr shows all outputs as disconnected after system suspend even though the monitors still display image

On an Arch Linux machine with Intel integrated graphics and motherboard with two connectors (HDMI and VGA), I've noticed that after the system wakes up, xrandr shows both outputs as disconnected, even though the monitors seem to work as intended with the right resolutions. It was only upon using software which, I assume, takes screen information from xrandr, like lightdm or mpv, that I discovered the issue. After boot, xrandr -q gives the expected output (in this case, a single monitor connected via VGA):

Screen 0: minimum 320 x 200, current 1366 x 768, maximum 16384 x 16384
HDMI-1 disconnected (normal left inverted right x axis y axis)
DP-1 connected primary 1366x768+0+0 (normal left inverted right x axis y axis) 410mm x 230mm
   1366x768      59.79*+
   1280x1024     75.02    60.02
   ...
   ...
   ...

After suspending and waking up, both outputs are disconnected:

Screen 0: minimum 320 x 200, current 1366 x 768, maximum 16384 x 16384
HDMI-1 disconnected (normal left inverted right x axis y axis)
DP-1 disconnected primary 1366x768+0+0 (normal left inverted right x axis y axis) 0mm x 0mm
  1366x768 (0x44) 85.500MHz +HSync +VSync
        h: width  1366 start 1436 end 1579 total 1792 skew    0 clock  47.71KHz
        v: height  768 start  771 end  774 total  798           clock  59.79Hz

If I try to change the mode at this point, the screen turns black. If I blindly write the output of xrandr -q to a file, it gives:

Screen 0: minimum 320 x 200, current 320 x 200, maximum 16384 x 16384
HDMI-1 disconnected (normal left inverted right x axis y axis)
DP-1 disconnected primary (normal left inverted right x axis y axis)

What could be the root of the issue? Can someone explain what's happening with the second xrandr output above? I have already tried different screens and cables and the issue persists. Where do I continue troubleshooting?