external monitor disabled upon editing file with vim

This is the strangest bug I've encountered in my 20+ years of linux use.
See a video of the bug at: https://drive.google.com/file/d/1StYD5kbL5pLRBOc6V-TXuE5DgymTdM0R/view?usp=sharing

Using an external monitor I am editing a Snakefile with vim and syntax highlighting. Under certain condition the monitor will go to sleep.

0. download the Snakefile, vimrc, and the colorscheme that are the attached archive
1. move the colorscheme to ~/.vim/colors/
1. `vim -u vimrc Snakefile`
2. delete one of the quotes, and see the external monitor go into sleep mode.

Pertinent points:
- If I disable the custom colorscheme or disable syntax highlighting there is no problem.
- If I move the gnome-terminal onto the builtin display, then the external monitor reactivates.

I wouldn't normally report this bug because it seems so specific to my setup. What is alarming is that a vim session in a gnome-terminal, under certain conditions, can cause the monitor to go to sleep!

ProblemType: Bug
DistroRelease: Ubuntu 21.04
Package: libwayland-client0 1.18.0-2~exp1.1
ProcVersionSignature: Ubuntu 5.11.0-17.18-generic 5.11.12
Uname: Linux 5.11.0-17-generic x86_64
NonfreeKernelModules: wl
.tmp.unity_support_test.0:

ApportVersion: 2.20.11-0ubuntu65
Architecture: amd64
BootLog: Error: [Errno 13] Permission denied: '/var/log/boot.log'
CasperMD5CheckResult: unknown
CompositorRunning: None
CurrentDesktop: ubuntu:GNOME
CurrentDmesg: Error: command ['pkexec', 'dmesg'] failed with exit code 126: Error executing command as another user: Request dismissed
Date: Wed May 19 12:14:23 2021
DistUpgraded: 2021-04-27 09:44:28,765 ERROR got error from PostInstallScript ./xorg_fix_proprietary.py (g-io-error-quark: Failed to execute child process “./xorg_fix_proprietary.py”: Failed to execve: No such file or directory (1))
DistroCodename: hirsute
DistroVariant: ubuntu
DkmsStatus:
 bcmwl, 6.30.223.271+bdcom, 5.11.0-16-generic, x86_64: installed
 bcmwl, 6.30.223.271+bdcom, 5.11.0-17-generic, x86_64: installed
 facetimehd, 0.1, 5.11.0-16-generic, x86_64: installed
 facetimehd, 0.1, 5.11.0-17-generic, x86_64: installed
GraphicsCard:
 Intel Corporation Haswell-ULT Integrated Graphics Controller [8086:0a26] (rev 09) (prog-if 00 [VGA controller])
   Subsystem: Apple Inc. Haswell-ULT Integrated Graphics Controller [106b:011b]
InstallationDate: Installed on 2021-01-19 (119 days ago)
InstallationMedia: Ubuntu 20.10 "Groovy Gorilla" - Release amd64 (20201022)
MachineType: Apple Inc. MacBookAir6,2
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.11.0-17-generic root=UUID=418e02d0-7fe0-4fe3-a1c4-ac2167ada4fe ro quiet splash vt.handoff=7
SourcePackage: wayland
UpgradeStatus: Upgraded to hirsute on 2021-04-27 (22 days ago)
acpidump: Error: command ['pkexec', '/usr/share/apport/dump_acpi_tables.py'] failed with exit code 126: Error executing command as another user: Request dismissed
dmi.bios.date: 02/22/2021
dmi.bios.release: 0.1
dmi.bios.vendor: Apple Inc.
dmi.bios.version: 431.0.0.0.0
dmi.board.asset.tag: Base Board Asset Tag#
dmi.board.name: Mac-7DF21CB3ED6977E5
dmi.board.vendor: Apple Inc.
dmi.board.version: MacBookAir6,2
dmi.chassis.type: 10
dmi.chassis.vendor: Apple Inc.
dmi.chassis.version: Mac-7DF21CB3ED6977E5
dmi.modalias: dmi:bvnAppleInc.:bvr431.0.0.0.0:bd02/22/2021:br0.1:svnAppleInc.:pnMacBookAir6,2:pvr1.0:rvnAppleInc.:rnMac-7DF21CB3ED6977E5:rvrMacBookAir6,2:cvnAppleInc.:ct10:cvrMac-7DF21CB3ED6977E5:
dmi.product.family: MacBook Air
dmi.product.name: MacBookAir6,2
dmi.product.sku: System SKU#
dmi.product.version: 1.0
dmi.sys.vendor: Apple Inc.
version.compiz: compiz N/A
version.libdrm2: libdrm2 2.4.104-1build1
version.libgl1-mesa-dri: libgl1-mesa-dri 21.0.1-2
version.libgl1-mesa-glx: libgl1-mesa-glx 21.0.1-2
version.xserver-xorg-core: xserver-xorg-core 2:1.20.11-1ubuntu1
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.10.6-2build1
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:19.1.0-2
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20200714-1ubuntu1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.17-1