The Furnace accessibility

*What I expected to happen was for me to put fuel for my iron in the furnace and it wouldnt let me click on the fuel slot.
For me for add fuel for my iron.

*What actually happened was it wouldnt let me access the furnace slots.
Describe what happened here
No Furnace for me
Steps to Reproduce:
1. Put a step by step guide on how to trigger the bug here
2. Try to smelt or cook something.
3. ...It wont let you.