During play, when having a chestplate in the vanity slot it causes any other item in the chestplate slot to randomly unequip and equip eg: backpacks and elytras.

This does not only apply to the chestplate but it is an example.

It seems like the armor in the vanity slot wants to equip itself in the regular slot for a split second at random intervals, which can be proven by the increase and decrease in armor stats.

Version: 1.20.4
Mod version: 1.4