Furnace not working properly

So I was getting gold in the nether,and then went back I stayed on the portal for a while (it was on the purple animation for a while), and then went to my furnace on my base. I had iron smelting but when i tried to collect it (it was already smelted). It didn't let me collect it, i can only collect it by clicking and dragging the item to my inventory, and when I try to stack them. They don't stack. For example I have 63 iron in my chest and i have 20 in my inventory, and they don't stack. Also when I try to pick a world they all have that pause symbol.