Your friend probably didn’t update his graphic drivers yet or there is some other version mismatch (some people were speculating that it has also something to do with the Windows version) on his end. He may also be using an AMD GPU, as far as I know this issue only affects NVIDIA cards (because it is an NVIDIA driver issue).
One of your godot games is using “Forward+” which is a Vulkan based renderer (what changed in the drivers update) the other project is using “Compatibility” which is OpenGL based, which is rarely changed and more often suppported
as @gertkeno also pointed out, if he is for some reason using the Compatibility renderer he will also not see the artifacts because Compatibility uses OpenGL under the hood and this is an issue with Vulkan