I tried loading into Minecraft a created new a world and I chose to be a phantom. For some reason, I couldn't go through walls. I finally found what the problem was, for some reason, I can't go through walls wen using the lithium mod made by jellysquid_
pls fix this

thank you for your time
FireMeg

Title correction: Phantom origin not working with lithium

Update your Lithium version. :)