I use a Dell external monitor connected via HDMI to my laptop. That used to work for the past three months or so, but after a recent set of upgrades, it no longer works. I plug in the cable, and Ubuntu shows me the "Display’ interface – evidently noticing a connected device – but the HDMI display itself is not recognized. The monitor gets no signal from the HDMI port, and the display stays black.
xrandr
output below:
Screen 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*+ 48.00
Information about my system:
OS: Ubuntu 20.04 focal
Kernel: x86_64 Linux 5.4.0-39-generic
Uptime: 25m
Packages: 2285
Shell: bash 5.0.16
Resolution: 1920x1080
DE: Xfce
WM: Xfwm4
WM Theme: Greybird
GTK Theme: Greybird [GTK2]
Icon Theme: elementary-xfce-darker
Font: Noto Sans 9
Disk: 16G / 244G (7%)
CPU: Intel Core i9-9880H @ 16x 4.8GHz [56.0°C]
GPU: Intel Corporation UHD Graphics 630 (Mobile) (rev 02)
NVIDIA Corporation TU117M [GeForce GTX 1650 Mobile / Max-Q] (rev a1)
RAM: 3232MiB / 31725MiB
Bug Report output: nvidia-bug-report.log (1.1 MB)