This is posted on the EQ Live Forums
here. Posting it on these boards as well to try and minimize the
my UI is broken posts.
I tested this using several different custom UIs and the Default UI.
When Shrouded or in a "Monster Mission" one main inventory container slot is missing (only have 7, the last one, on bottom right, is missing) and the first slot, on top left, inside a container is missing. This missing slot inside a container affects all container slots in the Main Inventory and in the Bank. There is a screenshot on the EQ Forums post, I am not duplicating it here.
Hopefully this will be fixed during the maintenance patch today, but I am not holding my breath.