I figured out why the VFX on Leedsichtys's AOE abilities doesn't always show.

Leedsichtys's AOE attacks have bubble VFX to show how far it reaches, just like any AOE on land would cause a shockwave VFX to play.
However a lot of the time, this VFX (on Leedsichtys) doesn't show and you are left wondering how you got hit (If you're fighting a Leeds) or guessing if a target is within range (on Leeds).

While VFX for regular attack animations still play the AOE VFX doesn't play if Leedsichtys is:

1. Close to the ground.
2. Close to Rocks or other structures.
3. The part of the body that causes the AOE IS obstructed.
4. within shallow water.

The AOE VFX do not play under certain conditions.

They should play as to show the range of the ability, to all players involved.