It’s been a known issue for a long time. This is nothing new. It’s the reason the carbon theme is the default instead of the simple theme. You will always run into this issue anytime you have a unique wallpaper for each system, regardless of what theme it is.
if you want the tronkyfran theme to work, limit your systems and up your gpu split, or just stick to the pc for the tronkyfran theme.
As we don’t maintain emulationstation it is unlikely to be fixed anytime soon – if at all.