Items being placed on armor slots (/invsee issue)

Full output of /ess version:

Server log: Anything related to essentials and no exceptions.

EssentialsX config: Tested with default config.

Description

When using /invsee , if you move an item from their inventory to yours, sometimes the item is placed on the armours slots.

I've also tested on a fresh server with no plugins, just Essentials, and it happens too.

Steps to reproduce

Use /invsee
opens their inventory
You move an item of their inventory to yours several times until the item is placed on armour slots.

Expected behavior

No bugs.

Screenshots

EssentialsX / Essentials