Expected behavior

Throwing a potion of instant health with a level of 125 at a player will kill them regardless of their game mode, and a PlayerDeathEvent should be called.

Observed/Actual behavior

Regardless of the player's game mode, throwing potion of instant health with a level of 125 to any player will cause them to die, which is a bug that existed in the original Minecraft, but it is a bug in Paper that PlayerDeathEvent is not called.

Steps/models to reproduce

1. Add a plugin to detect and debug PlayerDeathEvent events. I used my own PlayerDeathDebugger. You can find it at the link below:
   https://github.com/KRonaeGit/PlayerDeathDebugger/releases/tag/v1.0.0
   https://github.com/KRonaeGit/PlayerDeathDebugger/tree/main/src/main

2. Enter the following command to obtain the potion of instant health with a level of 125 mentioned above:

/give @s splash_potion[minecraft:potion_contents={potion: "minecraft:water", custom_effects: [{show_icon: 1b, amplifier: 125b, id: "minecraft:instant_health"}]}]

3. Ensure that PlayerDeathEvent is called when dying in a normal way, such as by executing the /kill command.
4. Throw the potion at yourself. Verify that the player dies, but the PlayerDeathEvent is not called.

Plugin and Datapack List

/datapack list

There are 3 data pack(s) enabled: [vanilla (built-in)], [file/bukkit (world)], [paper (built-in)]
There are no more data packs available

/plugins

Server Plugins (5):
Bukkit Plugins:
 - PlayerDeathDebugger

Paper version

/version

Checking version... please wait...
This server is running Paper version 1.21.8-60-main@29c8822 (2025-09-06T21:49:13Z) (Implementing API version 1.21.8-R0.1-SNAPSHOT)
Your are running the latest version

Other

No response