Throwing a riptide enchanted trident with the slow falling effect while swimming up does not always play the trident launching animation.

Was able to reproduce after a few dozen attempts in 1.15.2.

Can confirm that this issue is still present in 21w05b.

Can confirm in 1.16.5 and 21w08b.

Can confirm in 1.17.1. Video attached.

Can confirm this behavior in 1.18 Pre-release 1. Here are some extra details regarding this problem.

The Bug:

The riptide launching animation and sounds occasionally aren't played when throwing riptide tridents whilst having the slow falling effect.

Steps to Reproduce:

• Enter a one block deep area of water.

• Give yourself the slow falling effect and obtain a trident enchanted with riptide.

/effect give @s minecraft:slow_falling 999 0
/give @s minecraft:trident{Enchantments:[{id:"minecraft:riptide",lvl:3}]}

• Whilst keeping afloat in the water, throw the trident enchanted with riptide.

• Take note as to whether or not the riptide launching animation and sounds occasionally aren't played when throwing riptide tridents whilst having the slow falling effect.

Observed Behavior:

The riptide launching animation and sounds occasionally aren't played when throwing riptide tridents whilst having the slow falling effect.

Expected Behavior:

The riptide launching animation and sounds would always be played when throwing riptide tridents whilst having the slow falling effect.

Can confirm in 1.19.

While this has a more recent confirmed version, this duplicates MC-164847 as it has much more attention and upkeep. The only difference with this issue is slow falling, which is not necessary to reproduce the issue but instead just makes it easier.