Projectile culling bug (Spark for example)

When I cast the Spark spell for several seconds, the number of projectiles fired decreases, and at some point, no projectiles are fired at all. After reaching this "threshold," firing resumes, but the number of projectiles fired is significantly reduced. It seems the game has a limit on the number of projectiles a character can fire at once, and since Spark has a duration, while the first projectiles fired are active, subsequent ones cannot be fired. This issue greatly hinders the ability to deal consistent damage to bosses and closed areas like the Simulacrum.