Summoning a fireball with this command /summon minecraft:fireball ~ ~ ~ {ExplosionPower:0,direction:[0.0,0.0,0.0]} using any ExplosionPower amount causes fireballs to disappear for a few seconds and then reappear. Using F3 + B to show hitboxes I found that they completely disappear. Fireballs in this state can't be interacted with. As a troubleshooting step I tried saving and quitting to the title screen which didn't fix the issue upon reopening the world. Closing and reopening the game didn't fix the issue either. Testing the issue in a new world fixes the disappearing and reappearing issue, but the fireball still can't be interacted with. Fireballs that come from Ghasts don't have this issue.