How to stop the explosion from blowing away the projectile?

I’m pretty sure the collision settings don’t affect the field system. I set it up exactly as you said. Guess what changed? Nothing. Nothing change. They affect everything that sets up the physics simulation.

this could be a lot of different things based on how you have it set up exactly

So you’re suspecting that something I did caused the collision settings to lose their effect? I can’t do that, and I don’t know if it’s possible. You can see what I’m doing by looking in the official documentation under Field Systems and looking at the images there.
Can you give a concrete example of what would cause this to happen?