Xorg and xrandr detect a connected monitor that doesn't exist

I'm on a laptop with no additional monitors connected, but when I run xrandr -q, the output lists two connected devices. Xfce's Display settings dialog also shows two monitors, and so does Xorg.0.log. Here's the xrandr -q output:

0: minimum 320 x 200, current 1920 x 1080, maximum 16384 x 16384
eDP-1 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 344mm x 194mm
   1920x1080     60.00*+  59.97    59.96    59.93    48.00  
   1680x1050     59.95    59.88  
   1600x1024     60.17  
   (omitting many more resolutions)
DP-1 connected 1024x768+0+0 (normal left inverted right x axis y axis) 0mm x 0mm
   1024x768      60.00*  
   800x600       60.32    56.25  
   848x480       60.00  
   640x480       59.94  
DP-2 disconnected (normal left inverted right x axis y axis)
DP-3 disconnected (normal left inverted right x axis y axis)

Is this normal? If not, what can I do to remove this imaginary monitor? Restarting the laptop (with no external monitors connected at any point) doesn't change anything. (My guess it that something about this is causing a weird display problem I have - my login screen starts at the wrong resolution, and afterward the resolution gets corrected but the virtual desktop sizes are wrong.) Here are related Xorg.0.log lines - DP-1 (the imaginary monitor) does not have an EDID, but it is listed as connected with initial mode 1024x768, and also seems to somehow cause eDP-1 (the actual laptop monitor) to use initial mode 1024x768 instead of 1920x1080; then it gets classified as a keyboard for some reason:

[    13.093] (II) modeset(0): Output eDP-1 has no monitor section
[    13.921] (II) modeset(0): Output DP-1 has no monitor section
[    13.921] (II) modeset(0): Output DP-2 has no monitor section
[    13.921] (II) modeset(0): Output DP-3 has no monitor section
[    13.923] (II) modeset(0): EDID for output eDP-1
[    13.923] (II) modeset(0): Manufacturer: BOE  Model: 853  Serial#: 0
[    13.923] (II) modeset(0): Year: 2018  Week: 48
[    13.923] (II) modeset(0): EDID Version: 1.4
(skipping a bunch more EDID information for eDP-1)
[    13.924] (II) modeset(0): Printing probed modes for output eDP-1
[    13.924] (II) modeset(0): Modeline "1920x1080"x60.0  141.72  1920 1968 2000 2124  1080 1083 1089 1112 +hsync -vsync (66.7 kHz eP)
[    13.924] (II) modeset(0): Modeline "1920x1080"x119.9  266.50  1920 1944 1960 2000  1080 1081 1084 1111 doublescan +hsync -vsync (133.2 kHz d)
[    13.924] (II) modeset(0): Modeline "1920x1080"x60.0  173.00  1920 2048 2248 2576  1080 1083 1088 1120 -hsync +vsync (67.2 kHz d)
(skipping a lot more modelines for eDP-1)
[    14.754] (II) modeset(0): EDID for output DP-1
[    14.754] (II) modeset(0): Printing probed modes for output DP-1
[    14.755] (II) modeset(0): Modeline "1024x768"x60.0   65.00  1024 1048 1184 1344  768 771 777 806 -hsync -vsync (48.4 kHz e)
[    14.755] (II) modeset(0): Modeline "800x600"x60.3   40.00  800 840 968 1056  600 601 605 628 +hsync +vsync (37.9 kHz e)
[    14.755] (II) modeset(0): Modeline "800x600"x56.2   36.00  800 824 896 1024  600 601 603 625 +hsync +vsync (35.2 kHz e)
[    14.755] (II) modeset(0): Modeline "848x480"x60.0   33.75  848 864 976 1088  480 486 494 517 +hsync +vsync (31.0 kHz e)
[    14.755] (II) modeset(0): Modeline "640x480"x59.9   25.18  640 656 752 800  480 490 492 525 -hsync -vsync (31.5 kHz e)
[    14.755] (II) modeset(0): EDID for output DP-2
[    14.755] (II) modeset(0): EDID for output DP-3
[    14.755] (II) modeset(0): Output eDP-1 connected
[    14.755] (II) modeset(0): Output DP-1 connected
[    14.755] (II) modeset(0): Output DP-2 disconnected
[    14.755] (II) modeset(0): Output DP-3 disconnected
[    14.755] (II) modeset(0): Using fuzzy aspect match for initial modes
[    14.755] (II) modeset(0): Output eDP-1 using initial mode 1024x768 +0+0
[    14.755] (II) modeset(0): Output DP-1 using initial mode 1024x768 +0+0
(skipping a bunch of lines that seem unrelated - let me know if I should paste the whole thing)
[    15.141] (II) config/udev: Adding input device DP-1 (/dev/input/event10)
[    15.142] (**) DP-1: Applying InputClass "libinput keyboard catchall"
[    15.142] (II) Using input driver 'libinput' for 'DP-1'
[    15.142] (**) DP-1: always reports core events
[    15.142] (**) Option "Device" "/dev/input/event10"
[    15.142] (**) Option "_source" "server/udev"
[    15.144] (II) event10 - DP-1: is tagged by udev as: Keyboard Pointingstick
[    15.144] (II) event10 - DP-1: device is a pointer
[    15.144] (II) event10 - DP-1: device is a keyboard
[    15.145] (II) event10 - DP-1: device removed
[    15.161] (II) libinput: DP-1: needs a virtual subdevice
[    15.162] (**) Option "config_info" "udev:/sys/devices/pci0000:00/0000:00:02.0/rc/rc0/input11/event10"
[    15.162] (II) XINPUT: Adding extended input device "DP-1" (type: MOUSE, id 9)
[    15.162] (**) Option "AccelerationScheme" "none"
[    15.162] (**) DP-1: (accel) selected scheme none/0
[    15.162] (**) DP-1: (accel) acceleration factor: 2.000
[    15.162] (**) DP-1: (accel) acceleration threshold: 4
[    15.164] (II) event10 - DP-1: is tagged by udev as: Keyboard Pointingstick
[    15.165] (II) event10 - DP-1: device is a pointer
[    15.165] (II) event10 - DP-1: device is a keyboard

Unfortunately my Xorg.0.log.old is from the same day and has the same issues, but I found an Xorg.1.log.old from last year which doesn't. It lists the same eDP-1, but doesn't list any information for DP-1 or classify it as a keyboard or list it as connected, and the initial display mode was 1920x1080 (which is what it should be):

[   942.577] (II) modeset(0): EDID for output DP-1
    [   942.577] (II) modeset(0): EDID for output DP-2
    [   942.577] (II) modeset(0): EDID for output DP-3
    [   942.577] (II) modeset(0): Output eDP-1 connected
    [   942.577] (II) modeset(0): Output DP-1 disconnected
    [   942.577] (II) modeset(0): Output DP-2 disconnected
    [   942.577] (II) modeset(0): Output DP-3 disconnected
    [   942.577] (II) modeset(0): Using exact sizes for initial modes
    [   942.577] (II) modeset(0): Output eDP-1 using initial mode 1920x1080 +0+0

I'm on a ThinkPad P1 with Xubuntu 20.04 and Xfce 4.14.