Current tool in use vanishes when hit by trident thrown by drowned

Twice this week tools currently in use vanish when hit by a trident while underwater.  It seems to be somewhat rare.  Once a bow while in combat.  Once a pickaxe while collecting coral.  Both were fully enchanted and had mending.  Both were in good repair status.  Both times I searched all around for the item incase it was dropped.  But it was gone.