Sorry to necrothread, but this one creeps in so easily and is a simple fix.
Double check the Projectile Movement Component, the X, Y, Z vectors. The X is usually set to 1000 by default, and this gets incorrectly added to the homing calculations, so objects tend to circle forever or this force may be jerkily overcome with sufficient maginitude (not sure, but likely).
I hope you solved this, it might be worth zeroing out the vectors on the component automatically if homing is switched on
The deeper I get into projectiles, for unusual purposes, the more I’m liking them. I’m gradually figuring out ways to make them smoother and more blended in velocity and rotation 