Customization with Minecraft - Server is not running proper client version

System Information

Field Value
Operating System Linux - Ubuntu 24.04.2 on x86_64
Product AMP ‘Phobos’ v2.6.2.2 (Mainline)
Virtualization None
Application Minecraft
Module MinecraftModule
Running in Container No
Current State Ready

Problem Description

Issue

FTB Modpack NeoTech should be running on minecraft version 1.20.4, but the server configuration is still installing 1.21.7, making it impossible for anyone with the actual modpack installed to connect. I’m not seeing a common sense way to change the minecraft client version back to 1.20.4

Reproduction Steps

  • Set up new server
  • Change settings
  • Updated server
  • Reset Server

See the modded Java server guide in the knowledge base