Comment 1 for bug 1940793

Additional information.
lsb_release -a:

No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 20.04.3 LTS
Release: 20.04
Codename: focal

screenfetch -n:
 cmeo@rodan
 OS: Ubuntu 20.04 focal
 Kernel: x86_64 Linux 5.4.0-81-generic
 Uptime: 28m
 Packages: 2814
 Shell: bash 5.0.17
 Resolution: 1920x2160
 DE: Unity 7.5.0
 WM: Compiz
 WM Theme: Ambiance
 GTK Theme: Ambiance [GTK2/3]
 Icon Theme: ubuntu-mono-dark
 Font: Ubuntu 11
 Disk: 136G / 455G (32%)
 CPU: Intel Core i7-6500U @ 4x 3.1GHz [51.0°C]
 GPU: Mesa Intel(R) HD Graphics 520 (SKL GT2)
 RAM: 3545MiB / 15480MiB
Digging into this further, I found that there are .desktop files that are working and some that are not.

The .desktop files which don't work were created by playonlinux. Here is an example:
[Desktop Entry]
Encoding=UTF-8
Name=WarInTheEast
Comment=PlayOnLinux
Type=Application
Exec=/usr/share/playonlinux/playonlinux --run "WarInTheEast" %F
Icon=/home/cmeo/.PlayOnLinux//icones/full_size/WarInTheEast
Name[fr_FR]=WarInTheEast
StartupWMClass=WarInTheEast.exe
Categories=
X-Desktop-File-Install-Version=0.24

And here is one that does work:
[Desktop Entry]
Type=Application
Name=Arduino IDE
GenericName=Arduino IDE
Comment=Open-source electronics prototyping platform
Exec="/home/cmeo/arduino-1.8.12/arduino"
Icon=arduino-arduinoide
Terminal=false
Categories=Development;IDE;Electronics;
MimeType=text/x-arduino;
Keywords=embedded electronics;electronics;avr;microcontroller;
StartupWMClass=processing-app-Base