Slime chunks not detected in single player world

[sonuvaharris]

The dark green border for slime chunks is not displayed, regardless enabling/disabling the setting or changing the Max Y value.

I tested this on 3 separate worlds, including one created in 1.20.1.

Fabric version 2.6-1.20.1
MC Version: 1.20.1 (fabric)

[invalidtask]

This still happens in latest 1.21 version

[henryyuyhy]

it seems that the seed of the world is not detected automatically, you have to fill in the seed every time you enter the world