Thanks for letting me know! Now that I read your original post again, it was probably a different bug than the one which was happening on linux. I got many players who played in browser so it's weird you were the only one encountering this bug so far.
8 days ago(+1)
it happen, i tryed again and it happen. I can confirm that i control the turtle that has disapear after mutation. I check the console, not sure it will help nor it will be send
Thank you so much! This was very helpful!
Essentaily the only place where I use look_at() is for disapearing turtle's GPUParticles3D to face the player and after the player takes control of the disapearing turtle, the player and the GPUPartiles3D have the same position and thus look_at() fails because it needs a nonzero length to work, which I definetely should have checked first.
But that's more of a consequence of your bug that lets you take control of disapearing turtle.