1st game, still going.

I crafted Cloak of Shadows for Tandis.  It was his chest armor for several turns and a few fights.

Then ... it vanished.  It is not on any unit, nor in my inventory.  It simply disappeared (and Tandis's chest armor slot was empty the next time I looked at it).

• I may have done a few Quit/Load iterations.  The save file (I have only one) did have the Cloak in it at some point.
• I didn't notice any combat effect that destroys an armor.

I conjecture that this is just a Load bug.