Minecraft Version
1.16.5

Forge Version
36.2.8

Mantle Version
1.6.147

Tinkers' Construct Version
3.3.0.312

Describe your issue
When making an armor item for the first time the item may be created without any NBT data. This leaves the item with 1 durability. This problem has more than one way to perform the glitch, notably when shift-crafting an item for the first time.

Reproduced with only Tinkers' Construct?
This may be a cross-mod interaction. If anyone has this issue, please narrow down the mods to Mantle + Tinkers' Construct and any other mods that cause the problem.

I cannot reproduce this in testing, so either it was fixed or its a mod conflict. Going to close.

If anyone can reproduce this in 3.3.2.324 or later, leave a comment and it can be looked into again.