Zombies converted to drowned will not drop tridents

I use this farm from silentwisperer on youtube, https://www.youtube.com/watch?v=eijiw38fAUc to convert zombies to drowned, however after killing hundreds of converted drowned, not 1 dropped a trident. A few dropped nautilus shells but no tridents. As stated on the wiki, https://minecraft.gamepedia.com/Drowned , In all editions, farms that convert zombies to drowned produce the usual zombie drops. In Bedrock Edition, such a farm also produces tridents and nautilus shells. In Java Edition, a drowned farm must be designed to harvest naturally-spawned drowned to produce tridents and nautilus shells.