I’ve tested your website using wpe-webkit-mir-kiosk and mir-kiosk on a “classic” Ubuntu 19.10 Desktop system. It works for me (and ought to work for any “classic” system):
sudo snap install mir-kiosk
sudo snap set mir-kiosk daemon=true
sudo snap restart mir-kiosk
# Orange "splash" & black screen with cursor
sudo snap install --beta wpe-webkit-mir-kiosk
sudo snap connect wpe-webkit-mir-kiosk:wayland
sudo snap set wpe-webkit-mir-kiosk url=https://www.neuralgalaxy.com
# Your site displays and works