If you take an item or block etc. from your "big" inventory and move it out of the screen and drop it, it dissapears, it should be trhown out, as if u took the item from the other tabs except the inventory one
Related issues
duplicates
Attachments
Comments
migrated
[media]
Duplicate of MC-5929 , please use the search function to see if your bug has already been submitted. Currently over 40% of tickets are being closed as duplicate.