2nd time of random lost Item

It happened now for the 2nd time since I started playing PoE2 that I have lost an Item.
The first time it was annoying, but didn't hurt me. Just some random Unique from a Tab I was moving around.
This time though, while again playing with my Stash-Tabs, my *equipped* Amulet got removed. I am already at Endgame and it's so expensive that I cannot replace it myself. Now my complete build is screwed and I can't even wear 2 of my other items anymore.

Is there please any way to look into this and restore? Without this playing doesn't make sense for me anymore :(

EDIT: After trying out a few more scenario's it seems that I am also no longer able to open the "Instilling Window" - so might be that my amulet is stuck in there?