Opened inventory via E, then tried to close inventory again with E, but it didn't close the inventory and just re-centered the cursor in the middle of the screen.
Happened in both Survival and Creative.
EDIT: When trying to get to the automatic search via pressing T in the creative inventory menu, inventory was exited and went straight to chat. Inventory was in search mode when re-entered via E.
SECOND EDIT: Pressing E inside the creative inventory search screen will just erase the current search and do nothing.