Can you run
ldd /path/to/appimage/or/bin/launcher | grep not
Same goes for just launching the program from terminal and checking for any errors.
Based on the link … maybe check loading the location in browser as well as your default browser selection.
And if webkit2gtk is installed.
pacman -Qs webkit2gtk
Things like neofetch are rather incomplete. If you wish to share system info pleae use inxi;
[HowTo] Provide System Information