I can confirm this behavior in both 1.18.1 and 22w05a.
This issue is occurring because the three strings used for the loading animation within the multiplayer server selection list, those being "O o o", "o O o", and "o o O", are hardcoded, hence why they are untranslatable.
Here's a code analysis of this issue.
Code Analysis:
The following is based on a decompiled version of Minecraft 1.18.1 using MCP-Reborn.
net.minecraft.client.gui.screens.multiplayer.ServerSelectionList.java
public class ServerSelectionList extends ObjectSelectionList<ServerSelectionList.Entry> {
...
public static class LANHeader extends ServerSelectionList.Entry {
...
public void render(PoseStack $ps, int $i0, int $i1, int $i2, int $i3, int $i4, int $i5, int $i6, boolean $b, float $f) {
...
String s;
switch((int)(Util.getMillis() / 300L % 4L)) {
case 0:
default:
s = "O o o";
break;
case 1:
case 3:
s = "o O o";
break;
case 2:
s = "o o O";
}
...
If we look at the above class, we can see that the strings used for the multiplayer loading animation, are hardcoded, therefore are untranslatable.
I can confirm this behavior in both 1.18.1 and 22w05a.
This issue is occurring because the three strings used for the loading animation within the multiplayer server selection list, those being "O o o", "o O o", and "o o O", are hardcoded, hence why they are untranslatable.
Here's a code analysis of this issue.
Code Analysis:
The following is based on a decompiled version of Minecraft 1.18.1 using MCP-Reborn.
net.minecraft.client.gui.screens.multiplayer.ServerSelectionList.java
If we look at the above class, we can see that the strings used for the multiplayer loading animation, are hardcoded, therefore are untranslatable.