Playing on Fabric Medieval Minecraft modpack V11
things-0.2.17+1.18
For some reason the jump boost stopped working on socks.
When held the NBT data for the item is

{
RepairCost: 1 as int,
Enchantments: [
{
id: "yigd:soulbound",
lvl: 1 as short
}
],
Speed: 2 as int,
Jumpy: 1 as byte,
JumpBoostDisabled: 1 as byte
}

I thought maybe a hotkey or something may have toggled them off as I was in a panic fighting a raid prior to noticing but there are no toggle keys anywhere that I can find.

Toggling Jumpy on socks is done by sprinting while sneaking. It is detailed in the Things guide

Given that this is almost certainly not a bug and simply a feature as detailed in the comment above, I will go ahead and close this as invalid
Cheers