[1.20.1] Severe server freeze when exiting Nether portal or entering End (no mods, Forge 1.20.1, Arch Linux)

[Grinhecker]

I'm experiencing a critical issue on a dedicated Arch Linux server running the latest Forge for Minecraft 1.20.1. When a player exits a Nether portal (not enters, and not via /tp) or teleports into the End via portal, the server completely freezes for 1–10 minutes. During this time, all commands are unresponsive, and the game world essentially locks up. This is with watchdog disabled.

Environment:

• OS: Arch Linux (latest packages)
• Java: OpenJDK 17 (up to date)
• Forge Version: Latest 1.20.1 (tested multiple versions from the past ~3 months)
• Mods: None (issue occurs on a clean install)
• Server Type: Proxmox VM with:
• 4 virtual cores
• 64 GB RAM (63 GB allocated via -Xmx and -Xms flags)

Observed Behavior:

• Observed Behavior:
• The server freezes for 1–10 minutes when:
• Exiting a Nether portal (entering does not trigger the issue)
• Entering or exiting the End using a portal
• Teleporting using commands (e.g., /tp) works only for the Nether; teleporting to the End via command also causes a freeze
• The issue occurs anywhere in the world, not tied to specific coordinates or builds
• During the freeze:
• The server becomes completely unresponsive to all commands and player actions
• No crash reports, no errors, and no warnings are logged
• CPU usage remains under 50%, and RAM usage stays around 6–14 GB
• After 1–10 minutes, the server recovers automatically and resumes normal operation

[TileEntity]

Did you check the logs?

[Grinhecker]

as I said, the logs are empty when this happens. It just freezes without any error and throws no errors or warnings

[Grinhecker]

UPDATE: this seems to be an Arch-specific issue. Switching to Ubuntu server fixed EVERYTHING.

[Brown]

Chunk loading maybe stalls the JVM during dimension travel? As you mentioned "no mods", you can still create a separate folder for mod files and keep the organized using this android file manager.

Edited Sunday at 02:20 PM by Brown