Trident doesn't respect AbstractArrow

What behaviour is expected:

The trident to do no damage.

What behaviour is observed:

Trident completely ignored all of the properties.

Steps/models to reproduce:

Listen to ProjectileHitEvent (send a message or something to make sure you know it's listened to), then something along the lines of the following Kotlin snippet

        val projectile = event.entity
// code...
        if (projectile is AbstractArrow) {
            if (projectile is Arrow) {
                projectile.clearCustomEffects()
            }
            projectile.fireTicks = 0 // not known if ignored
            projectile.knockbackStrength = 0 // ignored
            projectile.damage = 0.0 // ignored
            projectile.isCritical = false // not known if ignored
            projectile.pierceLevel = 0 // not known if ignored
        }

        if (main.config.pvpMessage) {
            val msg = when {
                damagerState -> main.messages.pvpNoPvpTarget
                damagedState -> main.messages.pvpNoPvpHitter
                else -> main.messages.pvpNoPvpHitter
            }
            shooter.sendMessage(
                msg.process("target" to damaged)
                    .colour()
            )
        }

Plugin list:

Only a plugin doing this. The project isn't touched in any other way.

Paper build number:

Start by reproducing the issue through ProjectileHitEvent using the Kotlin snippet and verify which AbstractArrow properties a trident ignores. Trace the trident entity's handling from that event, then confirm done when the listed properties are respected and the trident causes no damage as expected.