I have Dell Xps 9310 and Dell 22" monitor plugged in via DVI-to-HDMI and HDMI-to-USB C.
I can use the external monitor with the same cable/connection on Windows without problem, but on Ubuntu 20.04, the external monitor displays whole start up and when I enter my password and open the system, the monitor shows the display just for 5 seconds and then enters into the power saving mode.
I found a similar issue here but I couldn't solve this problem:
my xrandr -q output:
Screen 0: minimum 320 x 200, current 3600 x 1317, maximum 16384 x 16384
eDP-1 connected primary 1920x1200+1680+0 (normal left inverted right x axis y axis) 288mm x 180mm
1920x1200 59.95*+ 59.88 47.96
1920x1080 60.01 59.97 59.96 59.93
1600x1200 60.00
1680x1050 59.95 59.88
1600x1024 60.17
1400x1050 59.98
1600x900 59.99 59.94 59.95 59.82
1280x1024 60.02
1440x900 59.89
1400x900 59.96 59.88
1280x960 60.00
1440x810 60.00 59.97
1368x768 59.88 59.85
1360x768 59.80 59.96
1280x800 59.99 59.97 59.81 59.91
1152x864 60.00
1280x720 60.00 59.99 59.86 59.74
1024x768 60.04 60.00
960x720 60.00
928x696 60.05
896x672 60.01
1024x576 59.95 59.96 59.90 59.82
960x600 59.93 60.00
960x540 59.96 59.99 59.63 59.82
800x600 60.00 60.32 56.25
840x525 60.01 59.88
864x486 59.92 59.57
800x512 60.17
700x525 59.98
800x450 59.95 59.82
640x512 60.02
720x450 59.89
700x450 59.96 59.88
640x480 60.00 59.94
720x405 59.51 58.99
684x384 59.88 59.85
680x384 59.80 59.96
640x400 59.88 59.98
576x432 60.06
640x360 59.86 59.83 59.84 59.32
512x384 60.00
512x288 60.00 59.92
480x270 59.63 59.82
400x300 60.32 56.34
432x243 59.92 59.57
320x240 60.05
360x202 59.51 59.13
320x180 59.84 59.32
DP-1 disconnected (normal left inverted right x axis y axis)
HDMI-1 disconnected (normal left inverted right x axis y axis)
DP-2 disconnected (normal left inverted right x axis y axis)
DP-3 connected 1680x1050+0+267 (normal left inverted right x axis y axis) 473mm x 296mm
1680x1050 59.95*+
1280x1024 75.02 60.02
1152x864 75.00
1024x768 75.03 60.00
800x600 75.00 60.32
640x480 75.00 59.94
720x400 70.08
DP-4 disconnected (normal left inverted right x axis y axis)
As you can see, Ubuntu detects two displays: DP-1 and DP-3. How can I make my external monitor (DP-3) display the screen continuously?
