Armor values are a bit messy:
A default mcreator armor has got these numbers in the editor (helmet, body, leggings, boots) :
2, 7, 5, 3
I know that because of harvest tiers and minecraft formulas these numbers aren't the same in-game, but the bug is that... I don't know how to explain, but here are the actual in-game armor values of that 2,7,5,3 armor:
3, 5, 7, 2
While a vanilla iron armor is:
2,6,5,2
I am not saying that the default numbers in the editor should look like iron armor armor values, I am saying that what you set in the mod element editor is totally different to the actual in-game armor.
I don't know if this is a bug or if this was supposed to happen.
sorry for bad English
Issue comments
In minecraft code, chestplates and leggings are the other way round for some reason. For example, in the code that defines the armour values, if I put 3,5,7,2, then leggings are 5 and chestplate is 7, likewise if I put 3,7,5,2 then leggings are 7 and chestplate is 5. Hopefully this helps!
Thank you for this bug report. We will check whether the values are swapped and fix this in such case.