A common way to dupe TNT. With the plugin enabled, the TNT is moved but is not duped or activated.

Description
This plugin prevents TNT from being duped by setting the TNT block-type to air if it is moved together with slime and detector rails. This results in the TNT to be moved, but it's not duping or exploding.

Installation:
1.0.1 is for older versions of Minecraft and Spigot.
1.0.2 is for Spigot 1.17 and Java 16.

1. Place "AntiTNTDupe.jar" in your Plugins folder.
Done!

If you can see "Enabling AntiTNTDupe v1.0.X" in the console, the plugin is loaded and will prevent TNT duping.

There is no configuration for this plugin.
Untested in 1.17, let me know how it works!