运行 xrandr --output eDP1 --scale 0.75x0.75 仅当插入辅助显示器时才会使我的主显示器变黑？

Question

我的主显示器的 DPI 不合理地大，因此在启动时我运行xrandr --output eDP1 --scale 0.75x0.75。由于~/.config/autostart/xrandr.desktop我的 Xubuntu 20.04 机器上有一个包含此命令的文件，因此此操作会自动完成。但是，只有当我的辅助显示器插入电源时，主显示器的屏幕才会变黑，这样我就只能看到鼠标。这还会使辅助显示器有点故障，屏幕会严重闪烁。可以通过等到命令运行完毕后再插入辅助显示器来防止此问题，但如果问题已经发生，我相信唯一的解决方法是注销、拔下辅助显示器，然后重新登录。

我应该从哪里开始诊断此问题的原因？这是一个已知的错误吗？

当一切正常运行时，这是我的xrandr输出：

$ xrandr
Screen 0: minimum 8 x 8, current 3840 x 1080, maximum 32767 x 32767
eDP1 connected primary 1440x810+0+0 (normal left inverted right x axis y axis) 310mm x 170mm
   1920x1080     60.06*+  59.93  
   1680x1050     59.88  
   1600x1024     60.17  
   1400x1050     59.98  
   1600x900      60.00    59.95    59.82  
   1280x1024     60.02  
   1440x900      59.89  
   1400x900      59.96    59.88  
   1280x960      60.00  
   1368x768      60.00    59.88    59.85  
   1360x768      59.80    59.96  
   1280x800      59.81    59.91  
   1152x864      60.00  
   1280x720      59.86    60.00    59.74  
   1024x768      60.00  
   1024x576      60.00    59.90    59.82  
   960x540       60.00    59.63    59.82  
   800x600       60.32    56.25  
   864x486       60.00    59.92    59.57  
   640x480       59.94  
   720x405       59.51    60.00    58.99  
   640x360       59.84    59.32    60.00  
HDMI1 connected 1920x1080+1920+0 (normal left inverted right x axis y axis) 530mm x 300mm
   1920x1080     60.00*+  50.00    59.94  
   1920x1080i    60.00    50.00    59.94  
   1600x900      60.00  
   1280x1024     75.02    60.02  
   1152x864      75.00  
   1280x720      60.00    50.00    59.94  
   1024x768      75.03    60.00  
   800x600       75.00    60.32  
   720x576       50.00  
   720x576i      50.00  
   720x480       60.00    59.94  
   720x480i      60.00    59.94  
   640x480       75.00    60.00    59.94  
   720x400       70.08  
VIRTUAL1 disconnected (normal left inverted right x axis y axis)

当我遇到相关问题时，这是我的xrandr输出：

$ xrandr
Screen 0: minimum 8 x 8, current 3840 x 1080, maximum 32767 x 32767
eDP1 connected primary 1440x810+0+0 (normal left inverted right x axis y axis) 310mm x 170mm
   1920x1080     60.06*+  59.93  
   1680x1050     59.88  
   1600x1024     60.17  
   1400x1050     59.98  
   1600x900      60.00    59.95    59.82  
   1280x1024     60.02  
   1440x900      59.89  
   1400x900      59.96    59.88  
   1280x960      60.00  
   1368x768      60.00    59.88    59.85  
   1360x768      59.80    59.96  
   1280x800      59.81    59.91  
   1152x864      60.00  
   1280x720      59.86    60.00    59.74  
   1024x768      60.00  
   1024x576      60.00    59.90    59.82  
   960x540       60.00    59.63    59.82  
   800x600       60.32    56.25  
   864x486       60.00    59.92    59.57  
   640x480       59.94  
   720x405       59.51    60.00    58.99  
   640x360       59.84    59.32    60.00  
HDMI1 connected 1920x1080+1920+0 (normal left inverted right x axis y axis) 530mm x 300mm
   1920x1080     60.00*+  50.00    59.94  
   1920x1080i    60.00    50.00    59.94  
   1600x900      60.00  
   1280x1024     75.02    60.02  
   1152x864      75.00  
   1280x720      60.00    50.00    59.94  
   1024x768      75.03    60.00  
   800x600       75.00    60.32  
   720x576       50.00  
   720x576i      50.00  
   720x480       60.00    59.94  
   720x480i      60.00    59.94  
   640x480       75.00    60.00    59.94  
   720x400       70.08  
VIRTUAL1 disconnected (normal left inverted right x axis y axis)