this has been posted a few times i think by other players... i can't remember what i'm supposed to do to show it again. I tried intialize. Then gave up. :D
Yep, TAB key does the trick.
I'd be interested to know if the jewel stats still add to your main stats when they don't show.
I was on a D grade and died amazingly quickly to two eyes. Then I noticed my jewels weren't showing in my inventory.
You still get the MDef from the jewels, it just doesn't show up in the Inventory. I think you can drag the jewels out from their place in the Inv. window, but I'm not sure as this has never happened to me.
this has been happening since interlude launched
its just a bug, yes you do still retain your m.def and they act like they are still equiped (at least in the many cases i have encountered)
has happened to me and/or friends for many random reasons
death, level gain/loss, kill a raid boss, etc.....
hold the tab button and watch that window flash open and close till they appear :P